市场情报 JNA Jan/Feb 2022 | 45 From left: 21.39-carat round sphalerite from SMGems Ltd, polished blue kyanite stones and chrome diopside 左起：SM Gems Ltd的21.39克拉的圆形闪锌矿，已打磨的蓝晶和铬透辉石 With a multitude of coloured gemstones available in the market today, consumers have at their disposal an ever-expanding assortment of choices, including non-conventional gems that are gradually catching up with their more popular counterparts in terms of demand and consumer interest. Apart from the winning trio of rubies, sapphires and emeralds, a great deal of coloured gems has since risen in status in the trade. Among the most favoured and commercially successful of these are tanzanite, tourmaline, spinel, peridot, opal, aquamarine, amethyst and garnet, to name a few. Their soaring prominence is largely attributed to mainstream use by leading jewellery maisons: A necklace adorned with an exceptional 131.21-carat spinel centre gem by Bulgari; an eclectic Brazilian aquamarine collection that includes rings, necklaces and earrings by Van Cleef & Arpels; and a variety of Boucheron jewellery pieces with tanzanite as centre stones. Influenced by buyers' constantly evolving preferences – shaped primarily by trade developments, increased awareness and education, and evolving social conventions – a number of lesser-known, non-traditional gemstones are gaining steam in the industry of late, particularly in mature gemstone and jewellery markets such as the US and Japan. Beauty in rarity At the centre of Noor Gems Japan Co Ltd’s booth at a recent jewellery exhibition in Hong Kong was a large pink gemstone, stunning in its subtle rosy hue and patent singularity. The uniquely facetted stone – a 19.06-carat pink zoisite – is in fact a pink tanzanite, according to the company’s Temur Ansari. “This gemstone is very rare. It is natural and unheated and comes in a special kite shape, which accentuates its exceptional colour and lustre,” noted Ansari. The stone sells for US$3,000 per carat. The highly admired tanzanite in vivid violet-blue colours is actually the blue variety of the mineral zoisite. Thanks to Tiffany & Co’s relentless efforts to feature the stone in its iconic collections, the blue tanzanite as we know today has amassed a huge following over the years. The jeweller coined the name tanzanite – based on the origin of the stone in Tanzania, East Africa. The rich blue hue of tanzanite can be achieved by heating natural zoisite, which comes in an array of colours including green, yellow, orange and, in very rare instances, pink. According to ASJ Gems, pink is the rarest of all zoisite colours and perhaps the most sought after by collectors. Another unique gemstone offered by Noor Gems is a pair of hemimorphite cabochons from Brazil weighing 103.51 carats in total. The gems exhibit an electric blue hue almost akin to a Paraiba tourmaline. The stone, which ranks 3.5 on the Mohs scale, is quite soft and is most suited for pendants or earrings. Smaller gems are best for rings, Ansari added. The gems sell for US$200 to US$500 per carat. The company official said hemimorphite is especially favoured by Japanese buyers. The Gemological Institute of America (GIA) earlier tested a 5.61-carat semi-transparent blue cabochon in its New York laboratory for a Paraiba tourmaline 6 to 7 6-7級 Tanzanite/zoisite ranks 6 to 7 on the Mohs scale. It has fair to poor toughness and a property called cleavage, which is a tendency to break when struck, according to the Gemological Institute of America. 坦桑石/黝帘石按莫氏矿物硬度标准属于第6至7级。美国宝石 学院(GIA)指出，其硬度介于普通至差之间，并且有称作解理 (Cleavage)的性质，受到敲击时有机会破裂。
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