Topacio Imperial
Topacio is a mineral with formula Al₂SiO₄(F,OH)₂, in the Silicatos (Nesosilicatos) group. This specimen comes from Ouro Preto, Ouro Preto, Minas Gerais, Brasil and joined the Terrium collection in 2025.
Description
Elongated, stout prismatic crystal with pronounced vertical striations, honey-golden colour, and high transparency in the upper third. It terminates in a slightly inclined pinacoid with minor surface irregularities. Shows a very weak, scattered reaction to ultraviolet light in the upper part. Its transparency places it at the boundary between a gemmological and a collector piece.
About Topacio
Topaz is an aluminium–fluorine nesosilicate with hardness 8 and perfect cleavage. The imperial variety is characterised by a warm colour range, high transparency, and prismatic habit. Brazilian pieces are the world standard for quality and typicality.
About the locality
Ouro Preto is the type locality of imperial topaz and the most famous source worldwide for this variety. Late-magmatic pegmatites produce prismatic crystals with warm hues, highly prized in gemmology and collecting.
Technical data
- Catalogue No.
- 0197
- Composition
- Al₂SiO₄(F,OH)₂
- Name
- Topacio
- Variety
- Imperial
- Group
- Silicatos (Nesosilicatos)
- Category
- Estélites
- Mine
- Ouro Preto
- District / Municipality
- Ouro Preto
- Province
- Minas Gerais
- Country
- Brasil
- Size (cm)
- 2 x 0.8 x 0.5
- Acquired
- 2025
- Etymology
- From the Greek "topazos", the name of an island in the Red Sea (now Zabargad), although the mineral so named was not topaz.
- Quality
- Muy buena
- Value trend
- Al alza
Related specimens
- Ágatha — Brasil
- Cianita — Brasil
- Cianita (Negra) — Brasil
- Cianita (Negra (Taramita)) — Brasil
- Clinocloro — Italia
- Amatista — Brasil
- Cuarzo — Brasil
- Elbaíta (Verdelita) — Brasil