Images
Formula: Cu2Te6+O4(OH)2
Tellurate
Crystal System: Monoclinic
Specific gravity: 5.43 calculated
Hardness: 3 to 3½
Streak: Pale leaf-green
Colour: Medium leaf-green
Environments
Localities
At the type locality, the Centennial Eureka mine, Eureka, Tintic Mining District, Juab County, Utah, USA,
frankhawthorneite has been identified on six specimens collected from the dumps of the mine.
The immense dumps were largely removed and processed for their low-grade concentrations of
gold in late 1991. At this time, a wide variety of mineralised samples were
exposed. Frankhawthorneite was observed in two boulders, and is very rare. On the holotype specimen, the
mineral is found in two interconnected vugs, approximately 2 mm in length, where it occurs as isolated crystals or
crystal groups that are perched on drusy white to colourless quartz. The
quartz, in turn, has been coated by a thin veneer of olive-green
cryptocrystalline mcalpineite. Associated minerals include
pyrite grains partially replaced by
hematite, acanthite,
chrysocolla, connellite,
enargite, hinsdalite,
svanbergite and an undefined
copper-, zinc- and
tellurium- bearing pale green botryoidal crust. Additional
copper-and tellurium- bearing
secondary minerals that have been identified on similar
specimens include cesbronite,
xocomecatlite, dugganite
and quetzalcoatlite. Frankhawthorneite is a
secondary mineral that formed from the breakdown of
primary copper-and
tellurium-bearing sulphides
(CM 33.641-647).
Frankhawthorneite from the Centennial Eureka mine -
Image
Back to Minerals