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 significant Cornish specimen of great rarity and quality. It consists of three large columnar crystals of steel-grey quartz, behind which are a number of smaller columns. All the large crystals have a hexagonal cross section, including the terminations. There is some twinning. A really good display specimen collected this year.

Location: Wheal Martyn China Clay Pit, St Austell, Cornwall, England.