I LOVE THESE THINGS! WHAT A NEAT EXAMPLE OF INTERESTING MINERALOGY, having talc replace a hard mineral like quartz!?! This is an incredibly rare pseudomorph of talc after quartz, on massive talc, from old Germany. Such large pieces are almost impossible to find. These pseudomorphs are quite old, and this one dates to the collection of Sir Robert Ferguson (1769-1840). He was a member of Parliament and the nobility from Kirkaldy, Scotland (he had stopped collecting by 1810, it is thought). I purchased it in London when his collection was dispersed in 1998, and sold it to a collector at that time. Unique to this location, the crystals are very sharp and have a soft vitreous luster. One of the hardest pseudomorphs to find in any condition and this piece is nearly perfect, AND OF LARGE SIZE. As you can imagine, this is a "must have" for any pseudomorph collector or historic mineral lover - and the two old labels are a bonus. For more on Robert Ferguson, click here: http://www.historyofparliamentonline.org/volume/1820-1832/member/ferguson-robert-1769-1840 Joe Budd Photos.