This is a brilliant vanadinite from Los Lamentos – these brown vanadinites were formerly referred to as the “endlichite” variety, and are now known as “vanadinite, var. arsenic-bearing” (catchy!). An older specimen, this piece was collected in the 1960s, and was in the collection of the A.E. Seaman Mineral Museum of Michigan Tech (collection specimen number GBR2008), before it was acquired by Gerald Panneton for his collection. The vanadinite crystals are sharp and incredibly lustrous. In excellent condition. This is a superb Los Lamentos vanadinite!