gems, quartz, rose quartz, Brazil, Teófilo Otoni, Minas Gerais

A gem dealer from Teófilo Otoni, Brazil, recently presented faceted colorless quartz with vivid pink banding, reportedly from the Araçuaí region of Minas Gerais. This unusual material, also seen in limited quantities at the 1993 Tucson gem shows, appeared as small faceted stones of a few carats. One 4.55-ct modified brilliant-cut oval examined by the West Coast lab showed a vivid pink face-up appearance, but closer inspection revealed densely packed thin pink bands within otherwise colorless quartz. While its gemological properties clearly identified it as quartz, the appropriate varietal name posed a challenge. EDXRF analysis showed only trace iron, yet UV-visible spectroscopy indicated absorption features more akin to amethyst than rose quartz, suggesting iron as the coloring agent. However, the stone lacked the purple color and rhombohedral zoning of amethyst, and its high transparency and distinct zoning did not match typical rose quartz. Given these distinctions, the stone was conservatively identified as “quartz,” with the unusual coloration noted descriptively rather than classified under an established variety name.