A sculptural and highly unusual, grape-like cluster of botryoidal, brownish-black cassiterite from a very uncommon Mexico locality. The botryoids are nicely accented by brick-red hematite flakes. 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 Charles Hansen Collection.