Chlorargirite. Also called cerargirite, ostwaldite, argiroceratite or horny silver, it is a mineral in the class of halide minerals, it precedes Broken Hill , Australia and was first described in 1565 .
Summary
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- 1 Features
- 2 Structure
- 3 Chemical properties
- 4 Related sites
- 5 Uses
- 6 Sources
characteristics
It is a secondary mineral that appears in the oxidation zone of silver mineral deposits, especially in regions with arid climates, due to the alteration and oxidation of minerals that contain silver, named in reference to its chemical composition of chlorine and silver ( argentum in Latin).
It is colorless and exposed to sunlight, it changes surprisingly from bright green, light yellow, gray and asyme, to a brown-violet hue. It is considered an isometric, hexoctahedral crystalline system with a hardness of 1.5 to 2.5 (Mohs); sectile toughness; density 5.57 and isotropic optical properties.
Structure
It forms cubic crystals, gathered in parallel, colorless or yellowish or gray aggregates. In principle, the chlorargirite is cubic and in some crystals it can appear in hexagonal shapes due to mixtures of faces of the cube with the octahedron and truncations that make it appear in the form of small deformed faces. Often these crystals form parallel or subparallel groups.
Sometimes massive, in microcrystalline silky luster crusts that fill the interior of geodes and drusen , sometimes as stalactites , or in coracoid aggregates, it has very rarely been found fibrous.
Chemical properties
The “cubic” chlorargirite is soluble in NH 4 OH.
It belongs to the so-called “chlorargirite group” or silver and copper halides , whose members are:
- bromargirite (AgBr)
- Chlorargirite (AgCl)
- iodargirite (AgI)
- marshita (CuI)
- Miersite ((Ag, Cu) I)
- nantoquita (CuCl)
The mineral is not usually pure silver chloride , as impurities that give it different shades of color are frequent, among which iodine is very frequent . There are a number of main varieties Bromine Chlorargirite with Bromine, Iodine-Bromine Chlorargirite with Iodine and Bromine (Buttermilcherz colloidal variety).
Related sites
There are minerals that appear associated with chlorargirite, some of them: carinthite, pelagite, silver, pyromorphite, malachite, limonite, jarosite, iodargirite, cerussite, bromargirite and atacamite.
Applications
It has been used for centuries as silver ore, searching for and extracting it in the mines for its high silver content.
