Apatite Cluster in Zambian Emerald
This author recently studied a 1.68 ct faceted emerald containing several inclusions, including blocky fluid inclusions, transparent brownish crystals, needles, and particle clouds. These inclusions as well as the trace element chemistry supported a Zambian geographic origin. The emerald also exhibited elongated transparent crystals that resembled amphibole. In this case, Raman spectroscopy confirmed the mineral as apatite. Interestingly, this apatite formed a distinct inclusion cluster consisting of a large hexagonal prismatic crystal (a morphology typical of the mineral) associated with a multitude of rod- and bamboo-shaped crystals in various directions (see above). Other solid crystals observed in Zambian emerald include mica, actinolite (amphibole), quartz, zircon, and chromite.
Apatite, a common phosphate mineral, has previously been reported in various forms and in many other types of gems such as corundum, spinel, feldspar, and garnet, and it is not surprising to find it in emerald. However, this is the first time the author has encountered this fantastic form of apatite in emerald.
