mystery quartz from an old European collection
22nd Jul 2018 07:47 UTCDon Windeler
I never get my hopes up with location-less specimens, much less one as common as quartz, but figure this one is just distinctive enough that it might get a hit.
I acquired this from a giveaway at a Bay Area Mineralogists meeting in 2010. It was previously in the "Wein" collection, which was built up in the late 19th / early 20th century and comprised primarily European specimens. Unfortunately I don't have any more details on the individual's name or location; it was purchased and disbursed 2008-2009 by John Veevaert, RIP. This was in the odds-and-ends left over, but based on the rest of the collection is most likely from somewhere in Europe.
The specimen is a single point, 12 cm high x 8.5 cm (max vertex to vertex) x 5 cm (min face to face). The core is dark smoky quartz, nearly opaque, which is coated by a 2 mm rind of iron-stained milky quartz. This first picture shows the display side; I'm going to eventually give it an Iron Out bath, but figured the coating might help with ID.
This second shot shows the back side and more of the smoky quartz interior. Based on one area where the milky quartz rind has flaked off, there is a very thin layer of muscovite flakes between the two quartz phases. This is in the center part of the photo. There re also mica flakes in the hematitic grunge coating the outside of the piece.
The bottom of the crystal (last photo) shows the smoky quartz with the outer rind. An interesting aspect is that the smoky quartz appears to have secondary regrowth, based on parallel trigonal faces that reflect the light at the same time. (Not apparent in this shot.) The middle of the crystal has a clot of muscovite crystals; this is dead center on the c-axis when I connect opposite hexagonal vertices. Please disregard the whitish chunk below the specimen, which is just a prop.
Any chance this rings a bell for someone?
Thank you,
D.
