What is ALEXANDRITE?
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Alexandrite is a variety of chrysoberyl that displays a color change depending on light conditions and the angle it is view from (pleochroism).The ideal color change would be fine emerald green to fine purplish red, but this is rare and expensive. Alexandrite was discovered in the Ural Mountains of Russia in the 1830's, and named after tsaravitch Alexander, the future tsar. That area was mined for over 60 years and still today Russian Alexandrite is considered the best quality. Today, small quantities of Alexandrite are mined in Brazil, Sri Lanka, India, Myanmar, Tanzania and Zimbabwe.
Color: Green in daylight and red-violet in incandescent light.
Hardness: 8.5
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What is AMBER?
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Amber is the fossilized resin from ancient forests. In ancient times the resin dripped and oozed down trees, filling fissures and trapping debris such as seeds, leaves, feathers and insects. The resin then became buried and fossilized through a natural polymerisation creating amber. The two main sources of amber in today's market are the Baltic states and the Dominican Republic. Amber from the Baltic states is older than that from the Dominican Republic is more likely to have insect inclusions. Most of the world's amber is in the range of 30-90 million years old. Semi-fossilized resin or sub-fossil amber is called copal.
Hardness: 2.5-3
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What is AMETHYST?
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Amethyst is a transparent purple quartz. Origin of name from the Greek -amethystos- "not drunken". Amethyst was considered to be an antidote against drunkenness. Different localities can produce a unique amethyst to that particular region or even to that particular mine. It is mined in Brazil, Uruguay, Bolivia and Argentina, Zambia, Namibia and other African countries. Very dark amethyst, mostly in small sizes, is also mined in Australia.
Color: the color range varies from pale lilac to deep purple.
Hardness: 7
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What is AQUAMARINE?
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Aquamarine belongs to the gemstone family of Beryls. Origin of name Latin "aqua" meaning water and "mar" sea. Legend has it that Mermaids tails were made of aquamarine. Aquamarine is usually free of inclusions and possesses a superior brilliance. The more intense the color of an Aquamarine, the higher its value. The principle supply of aquamarine stones comes from Brazil, Russia, Afghanistan, India and Pakistan
Color: pale blue to light greenish
Hardness: 7.5-8
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What is BLOODSTONE/ HELIOTROPE?
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Bloodstone or heliotrope, is a form of Chalcedony, a cryptocrystalline quartz. Bloodstone is green jasper with red inclusions. The red is sometimes caused by iron oxide or red jasper. Origin of name: From the red spots looking like spots of blood. It is usually cut "en cabochon" (that is shaped and polished usually with a flat bottom and a convex top) or into beads, it is used as a sealstone and in signet rings. Bloodstone is found in Australia, Brazil, China, India and the USA (Wyoming).
Color: green with red inclusions
Hardness: 7
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What is APATITE?
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Apatite is part of the phosphate mineral group. Origin of name: From Greek apate meaning deceit alluding to its similarity to other more valuable minerals such as olivine, peridot and beryl. Apatite is found in different worldwide locations like: Russia, Canada, Mexico, Spain and Africa.
Color: varies from being transparent to opaque, with colors ranging from yellow, green, blue, violet and colorless.
Hardness: 5
N.B. This stone is very sensitive to heat and care needs to be taken.
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What is CITRINE?
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Citrine is a form of quartz with ferric iron impurities and is rarely found naturally. Origin of name from the French word "citron" meaning lemon. Also called citrine quartz. Most commercial citrine is in fact heat treated amethyst or smoky quartz. Brazil is the leading producer of naturally mined citrine.
Color: the different shades range from yellow, gold, orange brown shades of transparent quartz.
Hardness: 7
N.B. Citrine and Amethyst are the exact same minerals, the only difference is the level of oxidation of the iron contained in the mineral. As this can be done artificially by heat or irradiation a large majority of Citrine sold today is heat treated amethyst. There are currently no scientific ways to determine if Citrine was changed artificially.
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What is CORAL?
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Precious coral or red coral is the common name given to Corallium rubrum. The hard skeleton of red coral branches is made up of mostly calcium carbonate and is durable and intensely colored. Coral can be polished to a glassy shine. Usually deep water corals have light color and shallow water corals have deep color. Coral jewellery has been found in ancient Egyptian and prehistoric European burials and continues to be made to the present day. Due to its softness and opacity, coral is usually cut as a cabochon or used to make beads.
Hardness: 3.5
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What is CUBIC ZIRCONIA?
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Cubic zirconia or CZ is a synthetic variant of the mineral baddeleyite which is extremely rare in nature. It is the oxide of the metallic element zirconium, zirconium dioxide. It was first used in the Russian space program to serve as a window to photograph through, it was not used in jewellery until 1969 when somebody decided to facet the material. It is often used as a diamond simulant. Cubic zirconia should not be confused with zircon, which is a rare naturally occurring gemstone.
Color: By adding other minerals in the creative process CZ's can come in any color as well as the colorless variety.
Hardness: 8.25-8.75
N.B. Key features that distinguish CZ from diamond:
Cubic zirconias have more dispersion than diamonds so show more fire.
A CZ has a Mohs rating of 8.5-9 and Diamonds have a rating of 10.
A CZ is 1.7 times heavier than a diamond of equivalent size.
CZs are optically flawless whereas the majority of diamonds have inclusions or flaws
CZ has a refractive index of 2.176, compared to a diamond's 2.417.
CZ can be made in most cases entirely colorless: equivalent to a perfect "D" on diamond's color grading scale but it is rare to find diamonds are truly colorless.
CZs are thermal insulators whilst diamonds are among the most efficient thermal conductors.
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What is DIAMOND?
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A diamond is a solid form of pure carbon with its atoms arranged in a crystal. Diamonds are the hardest naturally occurring substance. Origin of name: From Greek for invincible.
Color: it is rare to find diamonds are truly colorless.
Hardness: 10.00
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What is COLORED DIAMOND?
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Diamonds come in all colors but these natural Fancy Color Diamonds are rare and can be very expensive. One out of 10,000 normal diamonds is a fancy color diamond. The color of a fancy colored diamond is measured differently to a normal diamonds. The grading scale is based on the intensity of the color. The GIA fancy color grading scale is: Faint, Very Light, Light, Fancy Light, Fancy, Fancy Intense, Fancy Vivid, Fancy Deep and Fancy Dark.
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What is EMERALD
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Emerald is a valuable Beryl that owes its color to chromium or vanadium, which make it the bright green. Origin of name emerald is said to be a Sanskrit word meaning green (Sanskrit is a classical language of India). Emeralds can have many inclusions and flaws so can be brittle and liable to break. The value of an emerald depends on cut, color, clarity and carat. Clear stones with vibrant color command the highest prices. It is found in Brazil, Pakistan, Russia, East Africa, India, Madagascar and Columbia, at this point in time the best emeralds come from Colombia.
Color: Emeralds come in many shades of green and bluish green.
Hardness: 7.5-8
N.B. Many emeralds are treated to hide surface-reaching breaks and improve transparency.
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What is FIRE OPAL
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Fire opal is a bright orange variety of opal.
It is primarily found in Mexico, so is often known as Mexican fire opal. Fire opal was known to the Aztecs between about 1200 to 1519 AD
Color: Fire opals are transparent to translucent opals with warm body colors yellow, orange, orange-yellow or red.
Hardness:5.5- 6.5
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What is GARNET?
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Garnets are nesosilicates. 0rigin of name: from ancient Greeks as color reminded them of the pomegranate seed or granatum. Garnets do not show cleavage (the tendency of crystalline materials to split along definite planes, creating smooth surfaces) so when they fracture under stress, sharp irregular pieces are formed. Because the chemical composition of garnet varies, the atomic bonds in some species are better than in others. The harder species are often used for abrasive purposes. It is found in the regions of Kenya, Sri Lanka, Thailand, Brazil, India, Madagascar, Canada, USA, Czech Republic and Spain.
Color: virtually all colors
Hardness: 6-7.5
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What is IOLITE?
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Iolite is a blue silicate mineral that occurs as crystals or grains in igneous rocks, Origin of name: from the Greek ios, which means violet. Iolite changes colors (pleochism) depending upon which angle it is viewed from and the gems are cut to take advantage of that. It is found in Sri Lanka, Burma, Australia's Northern Territory, Namibia, Brazil, Tanzania, Madagascar, Connecticut, and the Yellowknife area of the Northwest Territories of Canada.
Color: Transparent, violet-blue, light blue, blue, rich blue-violet stone
Hardness 7.5
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What is IVORY?
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Ivory is a hard, white, opaque substance that is the bulk of the teeth and tusks of animals such as the elephant, hippopotamus, walrus, mammoth and narwhal. Ivory had been used for thousands of years for tools, implements and weapons and for carving and jewellery. The 1990 Convention on International Trade in Endangered Species (CITES) put a ban on international ivory sales to lessen the threat to endangered species by poaching. A species of hard nut sometimes called vegetable ivory or "tagua"is gaining popularity as a replacement for ivory.
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What is JADE?
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The term "jade" refers to two different, yet similar semi-precious metamorphic mineral gemstones, Jadeite and Nephrite. Nephrite and jadeite are resistance to breakage and chipping and due to their toughness they made a superior weapons and tools for early man. Not until the 19th century that a French mineralogist determined that jade was in fact two different materials. Nephrite is usually only green and creamy white, while jadeite can have the full range of jades colors. Jade is mined in the regions of Canada, Australia, United States and Taiwan.
Hardness: 6
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What is JASPER?
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Jasper is micro-crystalline quartz and is made from very small grains, it is a semi-translucent to opaque. Jasper has been used for thousands of years as tools and weapons during prehistoric times and for ornaments and jewellery later. Origin of name from the Greek iaspis. Jasper is commonly found in the regions of North Africa, Sicily, France, India, Venezuela and Germany, USA etc.
Color: dark green, yellow, brown, green, yellow, red and white.
Hardness: 6.5 to 7.5
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What is JET?
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Jet is a hard gem variety of Lignite. Jet is a type of brown coal, a fossilised wood of an ancient tree similar to our present monkey puzzle trees and cypress trees. These trees flourished in the Jurassic period when the trees died and fell they were eventually washed into rivers and seas to lie at the bottom for millions of years. All the other sediment built up causing great pressure, which flattened the wood and together with chemical changes altered the wood to jet. Jet has been used in Jewellery since ancient times and Queen Victoria wore Whitby jet as part of her mourning dress making it very popular.
Hardness: 2.5 to 4
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What is LAPIS LAZULI?
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Lapis lazuli is an opaque to translucent precious gemstone composed mainly of lazurite and calcite. Origin of name from the Persian "lazhward", which was the name of a place in modern Turkestan known for its deposits of lapis lazuli ("stone of lazhward"). The finest color is intense blue, lightly dusted with small flecks of golden pyrite. Polished Lapis can be made into jewellery. In the past it was also ground and processed to make the pigment Ultramarine for tempera paint and oil paint.
Color: Deep azure blue to light blue, bluish green
Hardness: 5.5-6
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What is LARIMAR?
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Larimar is a semi-precious blue variety of pectolite, Sodium Calcium Silicate Hydroxide. It was discovered in the Bahamas and Dominican Republic in the 1970's. The name Larimar comes from a combination of Larissa and Mar and was given to the stone by a Dominican who named the stone after his daughter Larissa and Mar, the Spanish word for sea. Although pectolite is found in many locations, none have the unique blue of larimar. This blue color, distinct from that of other pectolites, is the result of cobalt substitution for calcium.
Color: pale blue to sky blue
Hardness: 5
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What is MARCASITE?
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In jewellery, iron pyrite used as gem is improperly termed marcasite Origin of name from Arabic or Moorish for pyrite. Pyrite and Marcasite share the same exact chemical make up; however they both differ in their interior structure. Marcasite is frequently found in inexpensive silver jewellery and watches. It was fashionable and popular in Victorian and other times where it was often used to imitate diamonds. In better quality jewellery it is hand-set with grains or beads of metal from the setting being pushed over the edges of the stones. Marcasite occurs world-wide and is easily found in the chalk near Dover, Folkestone, and the French side of the English Channel.
Color: metallic
Hardness: 6-6.5
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What is MOISSANITE?
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Naturally occurring Moissanite was discovered in 1905 by Dr. F.H. Moissan, a French chemist and Nobel Prize winner and was named after him. Natural moissanite is very rare and is limited to iron-nickel meteorites. Virtually all of the moissanite sold in the world is synthetic. Synthetic moissanite is also known as silicon carbide after its chemistry (in industry moissanite is known as the man-made abrasive Carborundum). Moissanite is used as a diamond substitute as it is transparent and hard with a slightly higher refractive index than diamond. Moissanite jewels are cut to minimize their double refraction or birefringent effects. It is lighter and much more resistant to heat. This results in a stone of higher lustre, sharper facets and good resilience. Moissanite remains undamaged by temperatures used to melt gold.
Color: rarely clear to shades of very pale green.
Hardness: 9.5
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What is MOONSTONE?
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Moonstone is the best known gem variety of orthoclase feldspar. It is usually polished as a cabochon. Its importance as a gemstone arises because of adularescence, a floating light effect and sheen, compared to the light of the moon. This phenomena results from alternating layers of two kinds of feldspar, which cause light to scatter. Moonstone specimens commonly exhibit chatoyancy (a mobile, wavering striped reflection), and sometimes display a strong cat's eye.
Color: most desirable color of moonstone is blue, but it also occurs in grey, white, pink, green and brown.
Hardness: 6 to 6.5
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What is MYSTIC TOPAZ?
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Mystic topaz is a treated clear topaz, it is not found naturally. To create mystic topaz, natural, colorless topaz is coated with a thin layer of titanium. The coating is only microns thick and is applied to the stones pavilion, the underside angled portion that typically forms the bulk of the gem. The specialized coating alters the stones natural refraction, creating rainbow colors, predominantly blues, greens, yellows, and small bursts of red shades.
N.B. this stone should be treated with care
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What is ONYX?
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Onyx is a chalcedony that occurs in bands of different colors. Onyx refers to a black and white banded variety of Agate and brown varieties are named Sardonyx. It is composed of relatively straight, parallel layers of different colors. This structure lends itself to cameo making.
It is usually cut en cabochon, or into beads, and is also used for intaglios and cameos. Some onyx is natural but much is produced by the staining of agate. It is available in the regions of USA, Germany, Brazil, Mexico, India, and Africa.
Hardness: 7
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What is OPAL?
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Opal is a type of quartz. Origin of name: from Sanskrit (Sanskrit is a classical Indian language) upala = precious stone. They are luminous and iridescent with inclusions of many colors. Opals show a play-of-color (a shifting of spectral colors). Opals are found in the regions of Mexico, Brazil, USA, Japan, Honduras, Kenya, Czechoslovakia, Peru, Canada but by far Australia is the main source of opals, almost ninety-five per cent of all fine opals come from the dry and remote outback deserts.
Color: White, black, red, orange, most of the full spectrum, colorless, iridescent. Very infrequently of a singular color.
Hardness: 5.5- 6.5
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What is PEARL?
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Pearl is a smooth, lustrous, chiefly calcium carbonate organic gemstones. Natural pearls are nearly 100% nacre, a protective mother of pearl coating that is secreted to protect the organism for a foreign body that has entered the shell. Natural or real pearls come mainly from oysters, although there are other bi-valve molluscs which can produce them. Almost any species of bivalve or gastropod is capable of producing pearls. However, only a few species, such as the famous pearl oysters, can create pearls which are highly prized. Cultured pearls are produced by artificially introducing a foreign object into the fleshy part of oysters, which become coated with nacre in a similar manner to natural pearls. Imitation pearls, simulated pearls, have been produced for many years. Pearls are found in the regions of Japan, China, Tahiti, Australia, Indonesia, Philippines, USA and Burma.
Color: white or cream, but the color can vary according to the natural color of the nacre in the various species of mollusc used. Can also be black or various pastel shades. Pearls (especially freshwater pearls) can be dyed yellow, green, blue, brown, pink, purple, or black
Hardness: 3.5 to 4.0
N.B. To test if a pearl is natural, rub across your across the edge of your teeth; real pearl feels rough, simulated feel smooth.
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What is PERIDOT?
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Is the gem quality variety of the mineral olivine. Origin of name either the Arabic word faridat meaning "gem" or the French word peritot meaning "unclear". Peridot is one of the few gem stones that come in only one color. The depth of green depends on how much iron is contained in the crystal structure. Olivine is one of the most common minerals but the gem quality Peridot is rarer. It is found in the USA, Myanmar, Egypt, China, Sri Lanka and Pakistan.
Color: varies from yellow-green to olive to brownish green.
Hardness: 6.5 - 7
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What is QUARTZ?
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Quartz is a crystalline rock or mineral composed of silicon dioxide. Quartz is the second most common mineral in the Earth's continental crust and found in all types of geological environment. There are 49 variety's, a number of which are gemstones, some of which are very beautiful and very rare. Origin of name from Saxon word Querkluftertz = cross-vein ore.
Color: colorless, white, gray, yellow to brown to black, violet, pink
Hardness: 7
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What is RUBY?
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Ruby is the red variety of the mineral called Corundum which is composed of aluminium oxide (any other color of corundrum is a sapphire, see below). The red color is caused mainly by chromium and titanium. It is natural for rubies to have imperfections in them, including color impurities and inclusions of rutile needles known as "silk". Origin of name comes from ruber, Latin for red. Some rubies show a 3-point or 6-point star or asterism. These rubies are cut into cabochons to display this effect. Natural occurring rubies are very rare and extremely rare in large sizes over 3 carats. They can be found in many regions around the world from India, to East Africa, to South America, the Hindu Kush and a few deposits in the United States.
Color: pinkish red or deep, rich red color
Hardness: 9
N.B. Almost all rubies today are treated in some form (of which heat treatment is the most common practice) and rubies which are completely untreated and still of excellent quality command a large premium. Improvements used include color alteration, improving transparency by dissolving rutile inclusions, healing of fractures (cracks) or even completely filling them.
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What is SAPPHIRE?
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Sapphire is any color of the mineral corundum other than red, those are called ruby, (see above) corundum is composed of aluminium oxide. Sapphires tend to be translucent or transparent and have high amounts of refraction. The most desirable sapphires are generally those with an intense blue color with plenty of sparkle and life. Various shades of blue result from titanium and iron substitutions in the aluminium oxide crystal lattice. Some sapphires show a 3-point or 6-point star or asterism. These sapphires are cut into cabochons to display this effect. They can be found in Brazil, Tanzania, Sri Lanka, Kashmir, Thailand, Madagascar and Australia.
Color: Shades of blue, other colors- padparadscha (salmon pink), pink and purple, orange and yellow, green, and colorless and black. Each category has its own color range.
Hardness: 9
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What are COLORED SAPPHIRES?
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Sapphires are mainly known for their shades of blues, but they come in an assortment of colors.
Color: all colors across the spectrum including white and black.
Hardness: 9
N.B. It should be noted that many Sapphires can be treated to enhance or change their color. They are heated or irradiated to produce colors such as greens, yellows or even blues. While the color of Sapphires can be changed by intense heat and radiation, it is stable for daily wear jewellery.
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What is SHELL?
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Shells are organic minerals composed of calcium carbonate . Throughout the history shells of many types and from many different kinds of animals have been popular as human adornments. They are often used whole and drilled so that they can be threaded. The intricate design and varying color patterns of shells is mainly dependent on the diet of the animal the shell covers. Mother of pearl or nacre is created by molluscs such as oysters and abalones secreting a substances that consist of calcium carbonate. Nacre is continually deposited onto the inner surface of the animal's shell creating the iridescent nacreous layer or mother of pearl. This is done both as a means to thicken, strengthen and smooth the inner surface of the shell. Mother of pearl has been used as decoration from buttons to inlays in furniture, jewellery and much more for thousands of years. Mother of Pearl can be found in many regions including Japan, Australia, Europe and the United States.
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What is NATURAL SPINEL?
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Spinels are composed of magnesium aluminium oxide. Most Spinel is formed due to intense heat from volcanic activity or hydrothermal underwater streams. Origin of name: from Latin spinella meaning little thorn, after crystal shape. Spinels next to ruby and the rare red diamond, is the most expensive of all red gems. With a hardness of 8 and no cleavage planes, natural spinel is a tough and durable gemstone suitable for any kind of jewellery. Unfortunately most Spinel that is sold commercially is synthetic. Sri Lanka, Brazil, Thailand, and United States are most notable sources of natural spinel.
Color: cobalt blue, red to blue to mauve. Dark green, brown, black green, pink, deep pink with an orange tinge.
Hardness: 8
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What is TANZANITE?
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Tanzanite is part of the zoisite mineral species and is only found in East Africa. Discovered in 1967 in the Umba Valley near the Usambara Mts. in Tanzania. Tanzanite may be colorless, yellow-green, brown, or blue to violet when found; the crystals are heat treated to enhance their color.
Color: Tanzanite is noted for its remarkably strong trichroism, appearing alternately sapphire blue, violet, and sage-green depending on crystal orientation. (Trichroism is the property possessed by certain minerals of exhibiting three different colors when viewed from three different directions under white lights. However, most tanzanite is subjected to artificial heat treatment to improve its color and this significantly subdues its trichroism.
Hardness: 6.5
N.B: Tanzanite is a brittle stone and although it can be worn daily, care should be taken to protect it from knocks, pressure and extreme temperature changes. Do not use a home ultrasonic to clean jewellery with tanzanite
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What is TOPAZ?
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Topaz is a fluorosilicate and can contain trace elements that cause different colors within the Topaz. Origin of name: from Greek Topazion, a Red Sea Island often covered in mist. Topaz wasn't really known about before the classical era, in the Middle Ages the name topaz was used to refer to any yellow gemstone. Deposits of topaz are found in the regions of Russia, Siberia, Brazil, Sri Lanka, Africa and China, Japan, Pakistan, Myanmar, Nigeria, Australia, Mexico, and in the United States.
Color: Varies in a broad range of: yellow, blue, pink, peach, gold, green, red, and brown.
Hardness: 8
N.B. Topaz is often heated to change or enhance it's color.
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What is TOURMALINE?
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Tourmaline is one on the most complex gemstones of the silicate group and there are 10 different varieties created by the dozen or more elements they contain. Origin of name: from Sinhalese turamali = stone of mixed colors. There are Tourmalines, which change the color from daylight to artificial light and others display chattoyance(a mobile, wavering striped reflection).Tourmaline is found in Africa, Brazil, Madagascar, Mexico, Myanmar, Namibia, Sri Lanka and USA.
Color: depending on the variety green, red to pink, light to dark blue, colorless, purple , neon blue, brown, black, red to green and green to red.
Hardness: 7-7.5
N.B. Tourmaline may be heated to enhance it's color.
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What is TIGERS EYE?
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Tigers Eye is mainly composed of silicon dioxide, it is a form of quartz that acquires fine golden lustre when polished. Origin of name: the stone resembles the eye of a tiger. Tiger's eye is a semi precious stone with a rich yellow and golden brown stripes that display chattoyance(a mobile, wavering striped reflection). Tigers eye is found in regions of South Africa and Western Australia.
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What is TURQUOISE?
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Turquoise is composed of aluminium phosphate and copper. Origin of name: from French for Turkish stone as in ancient days it was transported through Turkey. It was very popular during the days of Ancient Egypt and Ancient Persia and known to man since at least 6,000 BC. Delicate veining, caused by impurities, is desired by some collectors as proof of a natural stone. Turquoise is found in the regions of Iran, southwestern United States, Africa, Australia, Tibet, China, Siberia and Europe.
Color: Blue, blue-green, green
Hardness: 5-6
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What is NATURAL ZIRCON?
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Zircon is zirconium silicate, belonging to the group of nesosilicates. Origin of name: from Arabic zarqun and Persian zar = gold, gun = color. Zircon is a natural forming mineral and it is not related to the synthetic diamond substitute Cubic Zirconium which is created in a laboratory. Zircon has a high refractive index and can be used to imitate diamonds. It is found in Australia, India, Brazil, and Florida, Cambodia, France, Myanmar, Thailand, Nigeria and Tanzania. Zircons found at Jack Hills in the Yilgarn Craton Western Australia are the oldest minerals found so far with an age of 4.404 billion years.
Color: Zircon can come in red, brown, yellow, green, black or colorless. The color of zircons below gem quality can be changed by heat treatment. Depending on the amount of heat applied, colorless, blue and golden-yellow zircons can be made.
Hardness: 7.5
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