Nestled in a matrix of ivory colored calcite, are several crystals of fluor-richterite, the largest of which is doubly terminated, black with good luster, and measures 5.2 cm in length. Fluor, richterite is a sodium calcium, magnesium, silicate, fluorite. Normally its a boring species I wouldn't care about or value highly as a display-quality mineral, but this one really stands out! The crystal is, by any standard, an excellent crystal of a black rarity that is so often seen as gravel and not as specimen-worthy.