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[Full title: Item-wise Discussion on Gems with Decreasing Hardness; (9): Jade]

Actinolite means 'ray' in Greek, and is a typical calcium-magnesium-iron (fibrous) amphibole silicate Ca, Mg, Fe) 5 (OH) 2 (S 14掳11) 2 Substitution by aluminium in this structure results in hard and interwining fibres and a family of gem minerals known. as JADE. These minerals may have hardness only 6-7, sometimes 5% in the Moh's scale and yet, on account of the fibrous structure these are exceptionally tough and difficult to fracture. Nephrite belongs to the amphibole group (double chain in the molecular level) whereas jadeite and chloromelanite belong to the single chain of pyroxene group. Nephrite may be white or green.

VII-48 due to iron and manganese. Apple-green or emerald green jadeite is so coloured, due to the presence of chromium. Black colour of chloramelanite is due to excess concentration of iron in the structure. Nephrite quarries in the Central Asia, in the Kuen-Lun mountains, Nan-Shan mountains in China etc. have been widely known. There is some nephrite in the southern part of the Mirzapur district in India. Good reserves of chloromelanite and jadeite ('yu in Chinese) occur in the sub-division of Mogoung in Upper Burma. The jade materials have been very popular in China and Central Asia, and extensively used to make a wide range of plates, bowls, vases, sword-handles and idols. A large number of Buddha images have been made out of jade, and in this connection use of jade became popular in India. Tagore quoted (1879: 512-513) a Sanskrit text describing pilu jade as smoke-coloured, white or green shaded with white, and hard, non-transparent and slightly lustrous': og dhutram sitam kheta harit kathoram asvaccham alpabhamativa pilu AFTER During the Muslim period of Indian history, jade was known not only as piln but also as yasam and jaharmuhra. We have indicated earlier that pilu stood for agate-carnelian also.