Laurelite with Anglesite

Availability

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Size

6 x 6 x 4 cm - Sm Cabinet 

Formula

Pb₇F₁₂Cl₂ (RRUFF)

Locality

Grand Reef mine, Graham Co., Arizona, United States

Large, silky-white to colorless compact fibrous or prismatic crystal groups of Laurelite. There are many more crystals than those photographed. Usually Laurelite crystals are microscopic acicular crystals occuring in bundles. These crystals are therefore untypically large and unsual in habit. They were verified by XRD. There are also the more trypical tiny acicular habit Laurelite crystals on the matrix.

The specimen as a whole is mineralogically a very interesting specimen which shows the paragenesis of the minerals produced. Unknown are the yellowish clusters which are somewhat pearly and flaky and very soft. The crystals are too small to XRD (I tried), but I don't know what EDS would show given the composition of these oxyhalides. Most of the colorless, equant crystals lining the cavity are Anglesite. The exterior wall contains a black oxide with a sooty overgrowth. There is also Caledonite and what seems to Boleite, although it is not reported at the Grand Reef.

Whoever is the lucky next owner of this specimen will have to do some work on the yellowish cluster as well as the secondary minerals along the exterior. May be some new minerals on this specimen.

Type Locality, XRD Confirmed