pegmatite
/ˈpɛɡmətʌɪt
/noun Geology
A coarsely crystalline granite or other igneous rock with crystals several centimetres in length: tourmaline occurs mainly in granites, pegmatites, and greisens [mass noun:, as modifier]: pegmatite dykes...
- It has also been found as a constituent of granites and in granitic pegmatites.
- Apatite is the most common phosphate mineral found in granitic pegmatites.
- Ed would drill by hand and blast away the rock, exposing the pegmatite.
Origin
Mid 19th century: from Greek pēgma, pēgmat- 'thing joined together' + -ite1.