While needles are common inclusions in many garnet species, this 2.30 ct pyrope-almandine garnet showcased them in a spectacular fashion (see above). The cluster of needles resembled a comet’s tail, with the needles intersecting at approximately 70 degrees in the center of the gemstone. The contrasting color of the needles with the red bodycolor of the garnet helps highlight this striking group of inclusions. Needle inclusions can provide important clues about a garnet’s formation, including pressure and temperature conditions during the growth process (J.A. Axler and J.J. Ague, “Oriented multiphase needles in garnet from ultrahigh-temperature granulites, Connecticut, U.S.A.,” American Mineralogist, Vol. 100, No. 10, 2015, pp. 2254–2271).
Isabelle Corvin is a gemologist in Olympia, Washington.
While needles are common inclusions in many garnet species, this 2.30 ct pyrope-almandine garnet showcased them in a spectacular fashion (see above). The cluster of needles resembled a comet’s tail, with the needles intersecting at approximately 70 degrees in the center of the gemstone. The contrasting color of the needles with the red bodycolor of the garnet helps highlight this striking group of inclusions. Needle inclusions can provide important clues about a garnet’s formation, including pressure and temperature conditions during the growth process (J.A. Axler and J.J. Ague, “Oriented multiphase needles in garnet from ultrahigh-temperature granulites, Connecticut, U.S.A.,” American Mineralogist, Vol. 100, No. 10, 2015, pp. 2254–2271).
Isabelle Corvin is a gemologist in Olympia, Washington.
