This is one of the largest Stillwellite-(Ce) crystals we are aware of! Stillwellite is a very rare cerium-lanthanum-calcium borosilicate and this particular specimen comes from the metamorphosed marbles in the area of the Dara-iPioz Glacier in Tajikistan, the world's best locality for the species. The big 2.5 x 2.4 x 2.3 cm, variegated brown to pinkish, lustrous crystal is hosted in a matrix of snow-white Calcite is sits noticeably atop this well composed piece. It is complete all around excepting a couple small dings which is expected of these crystals as they are frozen in the matrix and are difficult to expose. A fantastic specimen of this rare species! I purchased it long ago from Dr. Dmitriy Belakovskiy, of the Fersman Museum of Moscow.