(2) Gypsum ; the composition is the sulphate phase sulphate, which does not react with dilute hydrochloric acid. The hardness is 2 degrees, the knife can be scored, and the hard one is fibrous or dense. Soft sex is powdery. Its solution was titrated to a milky white with chlorination. (3) Glauber's salt ; the sulfate component sodium sulfate crystallizes well. It can be seen as a diamond-shaped crystal. It can be evaporated and crystallized. The evaporating crystals appear as "hairy" on the surface of the cuttings, with astringent taste and cool feeling. (4) Basalt; is a rock of volcanic eruption, gray and black and dark green common component mainly plagioclase, dense and hard, does not react with acids, mostly granular or massive debris. (5) Granite ; it is a kind of fire intrusion rock, very hard, mainly composed of feldspar, quartz , mica, etc. It is more common in meat red and black (more in variegated color) and does not react with hydrochloric acid. (6) Tuff ; is a volcanic eruptive rock with a rough surface, composed of black and white minerals, pyroxene, hornblende, feldspar and volcanic ash, etc., condensed structure, hard, non-reactive with acid, soil-like fracture Rough. (7) kaolin; mostly white, dense and creamy feel soft, aluminum silicate rocks earth, feldspar weathering often, sometimes associated with bauxite, with plastic, resistant to temperatures 350 ° c , and acid is not opposite. (8) White and evil; white, loose, soft and brittle, powdered, Aluminium Extrusions South Africa,Aluminium Profiles South Africa,Aluminium Window Profiles South Africa,Aluminium Profiles Pretoria Foshan Knilex Aluminum Co., Ltd. , https://www.aluprofilemaker.com
Simple identification of several common rocks
(1) Shale ; mostly with mudstone, except that it has a leaf structure and a smooth cut surface.