Figure F64. A euhedral crystal of zeolite (probably gmelinite or chabazite) in a secondary vein of opaque material (probably Mn oxyhydroxide) and calcite in Sample 192-1185B-5R-8 (Piece 3, 31-33 cm) (field of view = 5.5 mm; photomicrograph ID#s 1185B_203 and 1185B_204) A. Plane-polarized light. B. Crossed polars. Note the twinning in the zeolite.

Figure F64. A euhedral crystal of zeolite (probably gmelinite or chabazite) in a secondary vein of opaque material (probably Mn oxyhydroxide) and calcite in Sample 192-1185B-5R-8 (Piece 3, 31-33 cm) (field of view = 5.5 mm; photomicrograph ID#s 1185B_203 and 1185B_204) A. Plane-polarized light. B. Crossed polars. Note the twinning in the zeolite.