Phosphophyllite is one of the absolute Holy Grails of mineral collecting. In any size, they are the stuff of dreams - and this is a fabulous thumbnail, literally one of the finest we know of in existence for overall qualities in this size class (a few famous larger pieces exist, of course). Pieces like this came out of Bolivia in the 1940s or 1950s and so few survive. This is a special Phosphophyllite specimen because it is a full and balanced, almost completely gem thumbnail composed of three distinct twinned crystals, one larger crystal on either side of a slightly smaller, less conspicuous one. It constitutes a very fine and very rare twin with multiple crystals and quartz matrix for contrast. Most Phosphophyllites are simply singles - twinned or not, just singles. They are full thumbnails but not as volumetric as this - and it is that fat, volumetric presence that takes this to the next level, few others attain. The extra width also allows for more color, as color in this species is really proportional to crystal size, in most cases, so that at its best quality, the fatter the crystal the more intense the color. This stands out from nearly all other thumbnails I have seen for gemminess, crystal perfection and color. It is, for the person who appreciates this extra level of rarity, one of the ultimate thumbnail specimens. Like all such crystals of this quality, it would date from the mid-1900s finds in Bolivia. Many were brought out by the late Pete Bancroft, although the history on this specimen is not complete.