Tetrahedrite is a mineral comprising copper, antimony sulfosalt. It is the antimony endmember of the incessant firm solution sequence with arsenic containing tennantite. Other notable elements of its structure are mostly zinc and iron together with not so common silver, lead and mercury. Bismuth too replaces antimony site with bismuthian tetrahedrite or annivite being a documented variant. The associated silver dominant, mineral species freibergite, even though rare, is noteworthy as it may contain silver to an extent of 18%
Derivation of Name
Tetrahedrite derives its name from its crystals in characteristic tetrahedron shape. The mineral is generally found in huge form.
Tetrahedrite is among the most widespread ores, and occurs in layers of metamorphic rock. It is also found as tiny rocks on the surface, signifying a vein somewhere underneath. It is a trivial ore of copper plus associated metals.
At times, Tetrahedrite is used as gemstones.
Abundant quantities are found in Peru; Mexico; Broken Hill, Australia; Germany plus others.
Tetrahedrite shapes a firm solution sequence with the somewhat atypical mineral tennantite (Copper Arsenic Sulfide Cu12As4S13). The crystal structure of the two is similar but their percentage of antimony versus arsenic is different. Specimens rich in antimony are tetrahedrite whereas specimens rich in arsenic are tennantite. Some iron, silver and/or zinc always substitutes for copper in both the minerals to the extent of nearly 15 %. Tetrahedrite is an exceedingly common ore of copper plus silver. Smelting of tetrahedrite yields four copper bars plus 0-4 bars of silver (with a 20% likelihood of every silver bar getting produced).
Steel gray to iron-gray
4.6 to 5.2.
3.5 to 4