Parisite Crystals in a Colombian Emerald
The author recently examined a 1.21 ct transparent faceted emerald. Gemological observation and chemical and spectroscopic analysis indicated that this natural emerald originated from Colombia. Moreover, microscopic examination with a combination of oblique fiber-optic and darkfield illumination presented the classic jigsaw pattern with a three-phase inclusion; this type of primary fluid inclusion is relatively common in Colombian emeralds. Interestingly, oblique fiber-optic illumination detected some colorless transparent crystal inclusions surrounded by fluid, as seen in the above figure.
Raman microspectrometry analysis of the well-formed prismatic crystals indicated that the unusual fluorocarbonate minerals were parisite. These very rare parisite mineral inclusions have been found only in emeralds from the Muzo mine (Winter 1982 Lab Notes, p. 230; E.J. Gübelin and J.I. Koivula, Photoatlas of Inclusions in Gemstones, Vols. 1–3).
