A sculptural and highly unusual, layered nodule of botryoidal, lustrous, rich brown, cassiterite from a very uncommon Montana locality. This variety of cassiterite is called "stream tin", due to the rounded, stream-worn character of the cassiterite. Stream tin was named by Cornish miners from the streams, where the rich deposits were first found in Cornwall. This is excellent, old-time material from the Jaime Bird Collection [Rob Lavinsky sold 2009]. It has two labels attached with the numbers 472 and 4240.
"Wood tin," a cryptocrystalline variety of cassiterite, has bands that resemble the age rings of wood. This variety occurs in locations across the globe, and lapidaries sometimes create ornamental objects and cabochons from it.