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 An important gem mineral with several gem varieties. Qurtz varieties named according to their characteristic colour. Citrine--- yellow

Amethyst---------purple

Rock crystal-----colorless

Rose quartz------pink

Smoky quarts ---brown

At temperature up to 570c quartz is the stable modification of crystalline silica, SiO2. Quartz occurs in epithermal veins; it is a characteristic mineral of granite and granite pegmatite and is found in sand stones and quartzite.it occurs in hydrothermal metal deposits and in carbonate rocks where it is common. Details of a selection of significant location of ornamental/quality material are given with the type of quartz being discussed.

About NGJA

Srilanka the Gorgeous Pearl of The Indian Ocean is not only a beautiful Island nation veiled by the “Endless Sheets of Heaven” , The Magnificently Picturesque Nation is a “Treasure Island”, enriched with the astonishing splendor of vividly coloured bewitching gem stones that glitter to outshine the twinkling stars of a cloudless night.

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