gems, spinel, inclusions, pargasite

A 1.33 ct pink spinel containing a distinct mineral inclusion located near the stone’s surface was recently examined by the author. Raman analysis identified the inclusion as a pargasite (NaCa₂(Mg₄Al)(Si₆Al₂)O₂₂(OH)₂) crystal. This euhedral prismatic crystal displayed chamfered terminations, rhombohedral pinacoids, and a near-colorless bodycolor (figure 10). Reflected light highlighted a central feature, possibly a growth hillock, which gave the appearance of two connected pargasite crystals. While pargasite inclusions are more commonly found in corundum than in spinel, few have been documented exhibiting such remarkable morphology.