Abundant white, opaque calcite scalenohedral crystals to about 4 mm in vugs on matrix, accompanied by patches of botryoidal and sometimes iridescent goethite. Also present is an unknown mineral having a cubic to stacked cubic and sometimes elongated (almost acicular) crystal structure and metallic luster. Looks a bit like man made bismuth. Hematite or marcasite? Too small to capture adequately with my poor photographic skills. Could be something interesting! Self standing. Needs magnification to appreciate the unknown: hand lens, microscope or camera lens.