Short notes on the Chemical composition, Physical properties and uses of Microcline

Chemical composition: KAlSi₃0₈, (K, 0 = 16.9%, A1₂0₃ = 18.4% and SiO, 64.7%); in some varieties Na replaces K to certain extent.

Physical properties:

(i) Form: Commonly prismatic, stubby to elongate crystals are common. It also occurs in massive, lamellar and granular forms.

(ii) Colour: White, gray, pale yellow and bright green (Amazonstone).

(iii) Lustre: Vitreous to pearly.

(iv) Streak: White.

(v) Hardness: 6.

(vi) Cleavage: Perfect 2 sets.

(vii) Fracture: Conchoidal to uneven.

(viii) Specific gravity: 2.56.

(ix) Diaphaneity: Transparent to translucent.

Use:

Microcline is used in the manufacture of porcelain and pottery, for the production of glazes on earthenware, sanitary ware, enameled brick etc. It is also used in manufacture of opalescent glass, as a binder for abrasives and in facing of artificial building material. Amazonstone is used as an ornamental material.