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Formula: Pb3Zn3(Te6+O6)(AsO4)2
Tellurate,
dugganite group,
arsenic-bearing mineral
Crystal System: Trigonal
Specific gravity: 6.33 measured, 6.33 calculated
Hardness: 3
Streak: White
Colour: White, green
Luminescence: Not fluorescent under UV
Solubility: Quickly dissolves in even mildly alkaline water. Soluble in cold dilute nitric or hydrochloric acid, but
if more concentrated acid is used, or heating employed, it coats with Pb(NO3)2 or
PbCl2
(Mindat)
Environments
Localities
At the type locality, the Emerald Mine, Silver Plume Mine, Tombstone Mining District, Cochise County, Arizona, USA,
dugganite occurs as an alteration product of khinite and
khinite-3T, formed under acid oxidising conditions from
gold-telluride ores in massive
vein quartz. Associated minerals include
khinite, khinite-3T,
bromargyrite,
chlorargyrite, cerussite,
emmonsite, and other tellurium
oxysalts
(HOM).
Dugganite from the Emerald Mine - Image
At the Tintic Mining District, Juab County, Utah, USA, the first reported occurrence of dugganite was at the
Centennial Eureka mine, from which a single specimen with stubby pale green hexagonal crystals on a matrix of
quartz, associated with other
secondary tellurium
minerals, was reported. Since then, dugganite has been found at the Gold Chain mine, at the North Star upper
and lower dumps, and at the Trixie mine. At each of these localities it has been found as hexagonal crystals and
crusts, ranging in colour from green to blue-green, pale blue and tan. At the upper dumps of the North Star mine,
dugganite appears to be one of the last tellurium minerals to have
formed. It can be found even in heavily weathered rocks where all other
tellurium minerals have altered to
chrysocolla, with the dugganite occurring on top of the
pseudomorphs. At the North Star mine it has been found associated with
azurite, eurekadumpite,
goldfieldite and utahite. At
the Gold Chain mine, it has been found with dagenaisite,
eurekadumpite,
mcalpineite and sonoraite. At
the Trixie mine, it was found in a matrix of quartz with
goldfieldite, gold and
hessite. In all occurrences, individual crystals measure 300 microns or
less
(MinRec 55.2.198).
Dugganite from Tintic - Image
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