Veenite

veenite

boulangerite

launayite

sterryite

Images

Formula: Pb2(Sb,As)2S5
Sulphosalt, sartorite group, antimony- and arsenic- bearing mineral, forms a series with dufrénoysite
Crystal System: Monoclinic
Specific gravity: 5.92 measured, 5.96 calculated
Hardness: 3½ to 4
Streak: Black with weak brown tint
Colour: Steel-grey
Solubility: KOH (40%) tarnishes veenite iridescent and nitric acid tarnishes it black (Mindat)
Environments

Metamorphic environments

Localities

At the type locality, the Taylor Pit (Madoc), Huntingdon Township, Centre Hastings Municipality, Hastings County, Ontario, Canada, veenite occurs as small masses, stringers, and disseminated grains in marble developed in a sequence of metasediments near a contact with plutonic granitic gneiss (HOM).
Nearly all of the sulphosalt material consists of boulangerite and jamesonite; tetrahedrite, geocronite, and veenite are common but much less abundant. Veenite does not occur in weathered specimens, but masses up to 3/4 inch diameter have been found in situ at the site of the original prospect pit. Most veenite is massive or occurs as disseminated anhedral grains; the only available single crystal is more than half a millimeter long. Massive veenite is steel-grey in colour and resembles tetrahedrite (CM 9.1.7-24).
Launayite has been observed only in polished sections, where it occurs sparingly in association with veenite and boulangerite.
In thin sections, sterryite has been observed as needlelike laths which cut veenite parallel to its direction of polysynthetic twinning, and as single anhedral grains also associated with veenite (CM 9.2.191-213).
The proposed paragenetic sequence for lead - antimony - arsenic sulphosalts at Madoc, oldest to youngest, is antimony-bearing baumhaueriteguettarditeveenitetwinnitesorbyitesterryitemadocitearsenic-bearing boulangeritegeocroniteplayfairitelaunayiteboulangeritesemseyiterobinsonitezinkenite (CM 9.4.505-521).
Veenite from the Taylor Pit (Madoc) - Image

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