Quartz ("Beta Quartz") (ex Kay Robertson Collection)

Item Description

Please note that all "Beta Quartz" specimens are only Quartz paramorphs after Beta Quartz, as true Beta Quartz is unstable at room temperature. This is the same as Acanthite and Argentite, where Acanthite forms a paramorph after Argentite as the latter is only stable at a temperature over 177C. The specimens from Mollina, Spain are well-known to collectors, but seldom seen on the market. This piece is a great example of the material featuring the classic bi-pyramidal habit with a strong cognac-smoky color when backlit. Sharp, well-formed and doubly-terminated, but it does have a small contact on the back. A must have for any Quartz collector. Ex Kay Robertson Collection (#10251). Kay is a prominent California collector, who specialized in European classics (see the article in the March-April, 2007 Mineralogical Record and the 50+ page article in the German Magazine "Mineralien Welt" November-December 2017).