Description
Malachite is a Copper Carbonate mineral that often forms botryoidal, fibrous or stalagmitic masses. It is often the result of the weathering of Copper Ores and is commonly found with Azurite, Goethite and Calcite. It is typically associated with Copper deposits including Limestone which is the source of the Carbonate. Malachite is found in many regions worldwide and is usually shaded green in color.
Dioptase is an intense emerald-green to bluish-green copper cyclosilicate mineral. It is transparent to translucent. Dioptase is an uncommon mineral found mostly in desert regions where it forms as a secondary mineral in the oxidized zone of copper sulfide mineral deposits. However, the process of its formation is not simple, the oxidation of copper sulfides should be insufficient to crystallize dioptase as silica is normally minutely soluble in water except at highly alkaline pH. The oxidation of sulfides will generate highly acidic fluids rich in sulfuric acid that should suppress silica solubility. However, in dry climates and with enough time, especially in areas of a mineral deposit where acids are buffered by carbonate, minute quantities of silica may react with dissolved copper forming dioptase and chrysocolla.



