Oxides of the Semimetals and Metals

The minerals of this division are all rare in occurrence. Some of the more important species are, arsenolite, As₂O₃; senarmontite, Bb2O3; valentinite, Sb2O3; tellurite, TeO₂; tungstite, WO₃; cervantite, Sb₂O₄.

Oxides of the Metals
The oxides of the metals are grouped into two main divisions:

A. Anhydrous Oxides; B. Hydrous Oxides. Further, the Anhydrous Oxides are further subdivided into: (1) Protoxides; (2) Sesquioxides; (3) Intermediate Oxides; (4) Dioxides.

Anhydrous Oxides - Protoxides

Cuprite. Ruby Copper. Red Copper Ore
Composition. Cuprous oxide, Cu₂O 0 Oxygen 11.2, cooper 88.8.

Crystallization. Isometric. Common forms are cube, octahedron and dodecahedron, frequently in combination (Fig. 253). Sometimes in much elongates cubic crystals, capillary in size; known as “plush copper” or chalcotrichite.

Structure. Usually massive, more rarely in crystals or capillary forms.

Physical Properties. H. = 3.5-4.  G. = 6. Luster adamantine in clear crystallized varieties to sub metallic and earthy in massive varieties. Color ed of various shades. Ruby-red in transparent variety.

Test. Easily fusible at 3, giving emerald-green flame, or, azure-blue. Gives globule of copper on charcoal in R.F. When dissolved in small amount of concentrated hydrochloric acid and solution diluted with cold water gives a white precipitate of cuprous chloride (test for cuprous copper]). Usually to determined by its color and streak.

Occurrence. An important ore copper of secondary origin. Found in the upper. Oxidized portions of copper veins, associated with the other secondary copper minerals, native copper, malachite, azurite, chrysocolla, etc. Found in the United States in connection with the copper deposits at Bisbee, Morenci, etc., Arizona. An important ore in Chile, Bolivia, South Australia, New South Wales, French Congo,. Etc. Fine crystals come from Bisbee, Arizona; Cornwall, England; Chrssy, France; the Urals.

Name. Derived from the Latin, cuprum, copper.

Use. Ore of copper.