Gemstone City Trade Co.

Malaysia

Available in varying colours, shapes and transparency. Perfect for all types of creative designs or for jewellery where cheaper price points are necessary. We can changes minor measurements and shapes on site while you wait, but our large selection means we will most likely have the size already.

Tanzanite is a relatively new gemstone in the grand scheme of things, having only been discovered in 1967. It owes its name to the single source of its origin, the country of Tanzania. Unfortunately because of its limited geographical location it is widely believed that the worlds Tanzanite supply will be mined out within the next 30 years. The fact that it is pleochroic means that it often displays hues of both blue and violet depending on the angle which it is viewed. Although cutting can minimise or maximise the colours seen through the table of the stone through correct orientation and angles. Sometimes a beautiful colour play arises between the two that uniquely complements the stone. However it is generally famed for its deep royal blues that are said to rival sapphire in intensity of colour. Tanzanite does require heat to enhance the generally desired colours of blue or purple. This can occasionally occur naturally through processes such as bush fires but predominately it is achieved artificially. MOHS Hardness Scale: 6.5-7 Mineral Group: Zoisite Cleavage: Perfect

Topaz is one of the more common gemstones on the planet. However his should not stop them being treated as a beautiful option in the coloured world. Pure Topaz is white. It is mineral impurities that cause changes within its colour, and funnily enough it is these impurities that lead to increased price. Natural Pink and Imperial Topaz are generally the varieties that command the highest prices. Both of these come primarily from the most famous Topaz mine in the world; Ouro Preto, Brazil. The brilliant blue shades of topaz which they are mostly known for are usually achieved by artificial means. Topaz is exposed to radiation (a process known as irradiation) and then usually heated, to produce striking blue colours. A deep blue enhanced topaz is known as London blue; medium blue is called Swiss blue and light-blue is termed sky blue. Natural Blues do indeed exist but are generally a fainter greyish shade of blue. These weaker colours still command a higher price because of the fact it has not been artificially enhanced. Being a common gemstone, it is found all over the world. Some of the larger deposits are in Afghanistan, Australia, Brazil, Czech Republic, Germany, Italy, Japan, Mexico, Nigeria , Norway, Pakistan, Russia, Sri Lanka, Sweden, and the United States. Although topaz is a fairly hard gemstone it has perfect cleavage and is therefore susceptible to being damaged if struck upon a hard surface. Hardness (Mohs):8 Cleavage: Perfect

Tourmaline is a personal favourite here at The Gemstone Trading Company. They are quite tough and durable but the thing that sets them apart is the fact they come in all colours of the spectrum. These large contrasts in colour also lead to large contrasts in price, with more commonly found colours going for a pittance in relation to some of the more unusual or breathtaking colours on display. Copper-bearing tourmaline produce some of the most vivid and exclusive colours within this mineral family, producing neon greens and blues as well as electric purple varieties. Clean, top quality stones between 3 to 5 carats can demand well over $10, 000 USD per carat. Whereas darker common colours in the same carat bracket may go for as little as $50 USD per carat. The origins of the stone matches it colour array with a wide variety of sources around the world. Some of the more significants deposits are found in Afghanistan, Brazil, Madagascar, Mozambique, Namibia, Tanzania and Zimbabwe, but they are literally found all over the world. Some stones can be heated to improve both colour and clarity. Certain colours such as red and pink may also be enhanced through irradiation, although this only works on distinct shades from certain regions. It is nearly impossible to detect. Tourmaline has a curious property known as the pyroelectrical effect. A tourmaline crystal can become electrically charged due to processes such as rubbing. With this charge it will attract dust particles or small pieces of paper. Aware of this effect, the Dutch utilised hot Tourmaline stones to pull ash out of their smoking pipes! MOHS Hardness Scale: 7-7.5

PAIRSWe stock a range of matching pairs in the majority of gemstone varieties. From small to large these are best suited for earrings, shoulder stones or the savvy jewellery designer whose imagination exceeds basic design concepts. SETS AND SUITESAnything where three or more gemstones have been cut with the intention of selling together. This can be the exact same material so there is no colour variation or colours meant to compliment each other regardless of type.

The Gemstone Trading Co has a long history of being associated with the opal mining industry. From the early days with mining claims at Lightning Ridge, Coober Pedy and Andamooka through to the present day, we have always prided ourselves on sourcing and providing one of the widest and finest selections of opal available in Australia. Opals are the pride of the Australian gemstone world. Australia produces 96% of the worlds opal supply and beyond doubt the most brilliant displays of colour. Unlike other gems which require faceting or mineral impurities to create its beauty, opals have an inherent way of light diffraction that produces radiant burst of colour. It is truly a unique gemstone that comes in a wonderful array of colours, patterns and types. The many varieties include black opal, white opal, boulder opal, fire opal, Welo opal, crystal and matrix opal. The Gemstone Trading Company stocks all of these as well as doublets, triplets and opal specimens.

Spessartite comes from the Bavarian word, Spessart, which is a mountain range in Germany where spessartine garnet deposits were first found in the 1880s. Spessartite is synonymous with Spessartine, though in the gem trade the name Spessartite is more frequently used, and in the mineral trade the term Spessartine is more frequently used. Spessartite shot to attentions of many through an intense, vibrant deposit found in Namibia coined Mandarin Garnet. This deposit ran out years ago but the notoriety has remained. They have since found Mandarin varieties in Nigeria, Mozambique and Madagascar but the latter are generally littered with hazy inclusions that reduce the vibrancy of the stones. Spessartite is ideochromatic, meaning that it is coloured by a fundamental element in its composition. That element is manganese, which produces an orange colour. Aside from the bright mandarin colour they also produce neutral oranges and burnt oranges in abundance. They are able to exhibit deep red hues when iron is mixed in too. Unfortunately Spessartites will always be limited in popularity by the relative high quantities of the cheaper quartz substitute of Citrine that have very similar colours (although nothing comparable to the Mandarin class). It should be noted however that garnet is a harder more tenacious stone that has no known methods of enhancement. A much more attractive option for any real gem lover!

Aquamarines are one of the more recognised coloured gemstones in the world. Everyone has heard the name before and can immediately identify it in their minds with the colour blue. This however is not entirely true and should be more comparable in the mind to water. Just like different bodies of water, aquamarine can be light-blue, dark-blue, blue-green and green-blue. This is exhibited in its naming from Latin: aqua marina or water of the sea. The price of aquamarines is primarily dependent on the intensity of blue the stone exhibits. Deeper or more intense blues can triple the price of a sky blue aqua quite easily. Aquamarines are routinely heated to remove ferric iron content and hence mute green shades through the stone. Ironically green aquamarine is becoming quite popular in the market and merchants are left with heated stones of weaker shades of blue where their unheated counterparts before the green was removed would have likely moved much quicker and fetched a higher price. Perhaps the most famous mine of Aquamarine is the Santa Maria de Itabira mine in Brazil. The intensity of the blues mined there were unlike anything previously seen in the gemstone world. Recently Mozambique and Madagascar have found similar deep vivid blues. The term Santa Maria is now a term used to describe any deep intense blue in Aquamarine regardless of locality despite not being entirely correct.

Peridot is one of the few gemstones that comes in a single colour. The depth of green depends on its level of iron content. Higher amounts of ferrous iron in the stone will result in deeper, more vivid greens. These greens can be so strong that it has made for some powerhouse comparisons. It is believed that Cleopatras famed Emeralds that adorned her headdress were actually exceptionally large and beautiful Peridots. The ancient Romans shared this sentiment and called it evening emerald since its colour did not darken at night, and could still be appreciated under incandescent light such as candles. Peridot is the only facetable material found on this planet which can be extra-terrestrial in origin. 3 meteorites which facet grade Peridot have hit the planet. The Gemstone Trading Company is proud to be able to offer a selection of this with GIA certified stones cut from Admire, which was found in Kansas in 1881. Today, the most important deposits of Peridots are found in Pakistan and Mogok (Burma). Other lesser deposits are found in Australia (Queensland), Brazil, Kenya, Mexico, Norway, South Africa, Sri Lanka, Tanzania and the United States. Recently China has become of the largest producers of Peridot, although the quality is comparatively poor, producing yellowish or brownish greens or black inclusions.

Zircons rise to gemstone stardom has been subdued due to the fact it shares its name with cubic zirconia, a diamond simulant. For this reason Zircon has negative connotations of fake or imitation but this couldnt be further from the truth. Zircon is very real, completely natural and extremely beautiful. It is an interesting note that before diamond simulants could be created in the lab, white zircon was traded as the cheaper alternate to diamond. This was probably due to the fact that it has a high birefringence that provides a fire equal to diamond. It is also the oldest mineral on this planet, with a specimen found on a sheep ranch in Western Australia that is 4.4 billion years old! It comes in a verity of colours including blue, red, yellow, orange, green, brown and a range of combinations in between. But it is the Blue zircon, a variety of heated stone out of Cambodia or Burma that is the crown jewel of the zircon family. Gem dealer reports indicate that at least 80 percent of zircons sold are blue. This is primarily because of its electric colour which is both intense and beautiful. MOHS Hardness Scale: 6.5-7.5 Refractive Index: 1.810-2.024 Cleavage: Indistinct

The composition of rhodolite garnet is a mixture of pyrope and almandine garnet. Perhaps the most underrated and undervalued gemstone in the coloured world. Rhodolites produce intense shades of reds, pinks and purples which are generally very expensive colours to purchase. But due to its connotations with cheap red garnet and its relative broad availability it is still rather inexpensive. Recently they have found an intense purple deposit in Mozambique that looks similar to the finest royal purple Amethyst. This has been one of the few discoveries of new product in recent years.