Chalcanthite, Blue Vitriol Composition and Structure

Composition. Hydrous copper sulphate, CuSO4.5H2O = Sulfur trioxide 32,1, cupric oxide 31.8, water 36.1. crystallization. Triclinic. Crystals commonly tabular parallel to a pyramid face.

Structure. Crystallized, also massive in stalactic and reniform structure, sometimes with fibrous appearance.

Physical Properties. H. = 2.5. G. = 2.12-2.30. Vitreous luster. Color deep azur-blue. Transparent to translucent. Metallic taste

Test. Fusible at 3. Gives copper globule when fused with sodium carbonate on charcoal. Soluble in water. Dilute hydrochloric acid solution gives with barium chloride precipitate of barium sulphate. Much water in C.T characterized y its blue color and its solubility in water.

Occurrence. A mineral, found at times in arid regions as a secondary mineral, occurring near the surface in copper veins, and derived from the original copper sulfides by oxidation. Often deposited from the original copper sulfides by oxidation. Often deposited from the waters in copper mines. 

 Use. A minor ore of copper. The artificial blue vitriol is used in calico printing, in galvanic cells, and in various manufacturing industries.

Kalinite. Potassh Alum
A hydrous sulphate of aluminum and potassium, K2SO4. Al₂(SO₄)₃24H₂O. Isometric. Usually fibrous or massive. H. = 2-2.5. G. = 1.75. Vitreous luster. Colorless to white. Transparent to translucent. Fuses at 1 with swelling and gives a violet flame (potassium). Easily soluble in water. Astringent taste. Hydrochloric acid solution with barium chloride gives a white precipitate of barium sulphate, and with ammonium hydroxide. A comparatively rare mineral, which usually occurs as efflorescence on clays and slates, particularly those containing disseminated pyrite. Also at times in connection with sublimation products from volcanoes.