gems, beryl, emerald, Brazil, inclusions

In 2006, emeralds were discovered in the Fazenda Bonfim region of northeastern Brazil. Emerald mineralization occurs in association with small recrystallized pegmatitic bodies hosted by metamorphosed ultramafic rocks within the Santa Mônica Shear Zone. Prospecting and exploration have been conducted in a few small pits and tunnels, yielding emerald crystals with transparent areas typically ranging between 2 and 5 mm. Polished samples usually display a saturated bluish green color with a medium-light to medium tone. The most common internal features are partially healed fissures with two-phase (liquid–gas) fluid inclusions and a variety of fine, parallel-oriented growth tubes. The emeralds contain moderate amounts of the chromophore elements Cr and Fe, along with traces of V; they also show relatively high K and low Li contents. FTIR spectroscopic features are consistent with alkali-bearing emeralds that contain significant CO₂ and a small amount of deuterated water. Emeralds from Fazenda Bonfim can be distinguished from those of other schist- and pegmatite-related commercial deposits.