Parts of single crystals.
Crystals also have generally small blotchy inclusions of calcite.
Crushed sample treated with HCl. Richterite plus a trace of mica. Infrared spectra do not show a mica hydroxyl band. First Edition, U.S. Geological Survey Open File Report 87-263. Microprobe analysis by L. Walter shows sample to be homogeneous within and between grains, with a composition tyical of richterite.