Smoky Quartz gwindel w/ Chlorite (Belsky Coll.)

Item Description

There is no type of mineral specimen which more clearly says "Alpine classic" than the beautiful twisted-stack habit of quartz known as gwindel quartz. Typically sharp, lustrous and gemmy, always distinctive-looking, the colorless to dark smoky brown gwindels from the French and Swiss Alps have always been top-shelf collectors' items, according to a 2007 Mineralogical Record article by Tom Moore. Gwindel quartz is the intergrowth of (mostly) tabular quartz crystals in which the main crystallographic axes are more or less twisted with respect the neighbouring crystals. This results in a contorted (twisted) appearance. The reason for the twisting is the presence of a screw axis in the crystal structure (Zorz, 2009). They are found mainly in some alpine-type clefts. "Gwindel" is from German, meaning "gewunden" = contorted, twisted, wound. This classic specimen is water-clear, has a muted glassy luster caused by frosting/etching by chlorite and light smoky, tinted green (chlorite) color. For the size, this gemmy, frosted twisted gwindel smoky quartz is excellent. Chlorite-frosted twisted gwindels are relatively uncommon, in fact. The crystal looks good from either side. A cleave below the termination on one end is noted, but is a modest detraction. Ex Howard Belsky Collection. A nice "spiker" for this auction from the well known suite amassed by Belsky as a dealer and collector before his untimely passing in 1987.