Very large crystal of reddish-brown rutile, automorphic. One of the terminations is embedded in quartz, the other is incomplete.
Specimen from the Imfeld area in the Binn valley, in the upper Valais, Switzerland.
Rutile is a natural oxide of titanium that can occur either as gold, red, or black acicular crystals often within quartz, or as dark red crystals within highly metamorphic rocks.
This specimen is from the mineral collection of Deyrolle, a former naturalist dealer in Paris. It comes with its original label, which dates from the 1950s/1970s.
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