apatite

AP'ATITE, n. [From Gr. to deceive; it having been often mistaken for other minerals.]

A variety of phosphate of lime; generally crystallized in low, flat, hexahedral prisms, sometimes even tabular. Its powder phosphoresces on burning coals.

The phosporite of Werner includes the massive and earthy varieties of the phosphate, which are distinguished from the apatite, by their containing a small portion of fluoric acid.