Though the terms Jacinth and Hyacinth are no longer used in the gem trade, they are historically important names going back to biblical times. Yellow, orange, brown, or red variety of Zircon. Zircon is the traditional birthstone for December. The other color forms (yellow, green, pink, and purple) are less often seen in jewelry. It is often used as a cheaper, yet natural alternative to Diamond. Colorless Zircon is usually cut with a brilliant cut to bring out its fire to its fullest capability. Blue Zircon, the most popular color, has a lively pastel blue, and occasionally has a very desirable striking bright blue color. Zircon of all colors are used as gems, but blue, golden-brown, and white are the colors most often used. However, the two are entirely separate substances, and have no connection with each other except for the fact that they both contain the element zirconium in their chemical structure. Cubic Zirconia, a synthetic, inexpensive Diamond simulant, resembles colorless Zircon and has a similar sounding name. Zircon is sometimes confused with Cubic Zirconia. Zircons that are not faceted propely can appear blurry, due to strong double refraction. Another important factor when faceting Zircon is to minimize the appearance of its strong double refraction by cutting along proper angles. For this reason, care must also be taken when faceting Zircon gemstones. Zircon is also prone to cracking and chipping if banged too hard. This effect can be reversed by giving the stones a second heat treatment. An interesting and strange habit exhibited in only few Zircons is that their color darkens and their luster dulls upon prolonged exposure to sunlight. However, it does have some undesirable traits. The brilliant luster and fire of Zircon, combined with its good hardness and range of colors, make it a most desirable gem. Colorless Zircon is easily distinguished from Diamond by its strong double refraction and lower hardness. However, its popularity is somewhat diminished by the fact that it is often perceived as an inexpensive Diamond imitation. Its strong luster and intense fire gives it a real sparkle that is comparable to Diamond. Zircon comes closer to resembling Diamond than any other natural gem. No matter if we order from a factory or give our own rough for cutting, our local agents monitor the whole cutting process.White, Colorless, Blue, Red, Green, Yellow, Orange, Brown, Pink, Purple, Gray We buy eyeclean stones only from reliable suppliers - well, actually we, of course, buy all our stones from reliable sources only -) - and only if we get a chance to inspect the rough material ourselves. The rough piece contains a remnant of the seed crystals suspension wire Hydrothermally produced synthetic citrine The presence of colour zoning is not (any more) proof of natural origin. Be particularly alert with intensely coloured eyeclean stones. In most cases zoning will be nearly to completely invisible in a bezel setting.ĭistinct colour zoning, clearly visible in a cabochonĪttention: the market is flooded with synthetic citrines which are very hard to identify. When viewed from the top, colour should appear distributed evenly. In skilfully facetted stones the zoning is only visible when viewed from the side. Worth knowing:quartz crystals often sport distinct colour zoning which poses a challenge to the gemcutter. Be careful during soldering as colour change can occur at relatively low temperatures.Ĭitrine has no or only very weak cleavage and thus is unproblematic during setting. Two Palmyra Citrines (heat-treated) in concave cut and conventional cut Deep orange stones, sometimes with a reddish or slightly brownish tinge, are called Madeira Citrines. For yellowish orange stones of lighter tone the trade name Palmyra citrine has taken hold. The procedure is legitimate, accepted by the CIBJO and must be disclosed at the point of sale.Ĭolour: from pale yellow to orange. Most citrines offered by the gem trade are heat-treated amethysts or heat-treated smoky quartz.The colours of treated citrines are in general more intense and more attractive than those of natural citrines. Two naturally coloured citrines from Brazil The most important deposits are in Brazil and Russia. The colour is mostly rather pale, often with a slightly brownish (smoky) tinge. Localities: natural citrine is quite rare. Thank goodness these misleading terms, which were accepted trade names, are only rarely encountered today (and should be abandoned altogether).Ĭan be confused with: all yellow gemstones Synonyms and trade names: golden topaz, Madeira topaz Quartz is the reference stone for hardness 7 on Mohs´ scale of hardness
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