Gem News International Gems & Gemology, Summer 2016, Vol. 52, No. 2

African Rhodochrosite and Colombian Quartz with Trapiche Patterns


South African rhodochrosite specimen and Colombian quartz slices showing trapiche-like patterns.
Left: A 6.0 cm tall rhodochrosite specimen from the N’Chwaning mining area in South Africa. Right: These domed hexagonal quartz slices from Colombia, measuring 3.5–4.5 cm across, exhibit inclusions reminiscent of trapiche emerald. The pattern becomes more distinct when viewed through cross-polarized filters. Photos by Donna Beaton.

At Tucson's Pueblo show, Germán Salazar (Idar-Oberstein and Bogotá) and Gaetano Lacagnina (L.G. Gemme, Milan) shared a booth that featured an eclectic assortment of gems and minerals. Mr. Lacagnina, who also operates a lab and cutting factory, specializes in unusual and fine mineral specimens. Of particular note were high-quality rhodochrosites, as seen in the image on the left, from the N’Chwaning mining area in the Northern Cape province of South Africa. N’Chwaning, noted for having Africa’s largest manganese reserves, also produces manganite, ettringite, and other Mn-bearing minerals. Noteworthy on Mr. Salazar’s side of the booth were polished hexagonal quartz slices bearing a spoked trapiche-like pattern, shown in the right-hand image. Coincidentally, the quartz was from the Boyacá region of Colombia, which regularly produces trapiche emerald. The patterned areas are found at the core of larger quartz crystals. Viewed in a polariscope, the growth directions and fibrous inclusions are very distinct. Although Mr. Salazar has marketed the slices as “trapiche quartz,” he is considering branding this unique find as “Salazarite.”

Donna Beaton is colored stones technical advisor for content strategy at GIA.