An excellent thumbnail of rarities from the Corrego do Urucum Pegmatite of Brazil. A rich dusting of yellowish-brown stannomicrolite microcrystals coats glassy stokesite crystals. Stannomicrolite (a hydroxide) is the tin-rich member of the microlite subgroup of the pyrochlore group of minerals and is known from only three localities worldwide. Stokesite is a very rare calcium, tin silicate. Older material.