A dark brown, lustrous, coarse-grained mass of bannisterite with minor white calcite. The resemblance to mica is well shown in this specimen, but cleavage sheets of bannisterite are brittle rather than flexible. Franklin Mineral Museum specimen FMM-1133; ex SPEX/Gerstmann collection.
Identifier: BNS1a Locality: Franklin mine, Franklin Specimen size: 12.5 x 7.5 x 6 cm Photo credit: Earl R. Verbeek
