This specimen, like others in the Lockhart collection, is carefully chosen to represent the highest quality level of Gwindel Smoky Quartz in this size range, with sharp and gemmy crystals perched on matrix in aesthetic balance that is highly unusual for the material. Each gwindel crystal is windowpane transparent, and 4.5 cm across tip to tip. It is complete, unrepaired, and beautiful all around 360 degrees as you turn it. The crystals sit on a sparkling matrix of absolutely water-clear and gemmy small crystals of smoky quartz. You can look through them, to see the underlying granite matrix below. While single gwindels are common enough, such a "double" is exceedingly rare, especially on matrix and without repairs. This specimen was purchased directly from Swiss dealership Siber & Siber in 2015, from a summer 2014 discovery that they helped bring to market. Brent Lockhart was the first owner of this fine piece. An excellent summary of the more technical aspects of these amazing styles of quartz, called Gwindels after the German word for "twisted," can be found here: http://www.quartzpage.de/gwindel.html