Albite (NaAlSi₃O₈) is the sodium end-member of the plagioclase feldspar series and forms a complete solid-solution series with anorthite (Ca-endmember). Cleavelandite is the platy collector variety from pegmatite pockets — often paired with tourmaline, beryl, and lepidolite. Major rock-forming mineral in granites and pegmatites.
Key Facts
- Mohs hardness 6–6.5.
- Triclinic; classic “albite twinning” lamellae visible under polarized light.
- Cleavelandite is the bladed/platy variety treasured by pegmatite collectors.
- End-member of plagioclase: An0 (Ab100).
- Common matrix for elbaite, beryl, spodumene gem pegmatites worldwide.
Notable Localities
Minas Gerais (Brazil) and Pala (California) produce cleavelandite associated with gem tourmaline. Pakistan and Madagascar yield additional pegmatite specimens.
Found at these Localities
- Eastern Brazilian Pegmatite Province (巴西东部伟晶岩省)
