Chemical Formula: SiO2

Chemical Name: Silicon Dioxide

Mineral Class: Tectosilicate

Mineral Notes: Quartz is a widely found rock-building material found in many shapes and forms. It is one of the most commonly used materials by people, having uses in glass manufacture, electronic equipment, jewelry, decoration and in ancient days for producing sparks to start fires.

Description: A very attractive geode consisting of alternating bands of white and pale blue chalcedony. The center contains a cavity lined by well-formed, lavender-coloured crystals of Amethyst Quartz. A very aesthetic display specimen.

Location: Rio Managua, Minas Gerais, Brazil.