Finnemanite

Availability

Sold

Size

6 x 5.5 x 3 cm - Sm Cabinet 

Formula

Pb₅(As³⁺O₃)₃Cl (RRUFF)

Locality

Långban, Filipstad, Värmland, Sweden

Tagged

arsenate

Here's a Langban treasure highly sought after and exceedingly rare. It has been verified by XRD. Both sides contain flat lying dark grey, elongated, crystals, mal-formed probably from tight conditions which would restrict the growth. The longest crystal is 1cm with numerous smaller crystals. It is much like the photo in the photo on page 118 of the Langban book by Bollmark et al. Granted they are not exposed as much however the matrix is the same, a granular hematite, as well as  the reddish orange or yellowish crust in which the crystals grew. The backside has numerous crystals also just as obvious under a scope. There is a small 1mm to less veinlet along the side of the specimen, which also has one small crystal.The adamantine luster is much like that of cerussite. The prismatic nature is unlike cerussite however. It's a definte match as shown on the XRD pattern.

It has an old inked number on the backside, unfortunately I do not have the old label to go with the number. But there is one label typed on the backside of an old business card from "Camden Mineral Company" of a one E. W. Rushton from Camden, Maine.

Type Locality, XRD Confirmed