silicates
Albite
Na(AlSi3O8)
- Also known as
- cleavelanditeperisterite
- Crystal system
- triclinic
- Hardness
- 6–6.5 on the Mohs scale
- Lustre
- vitreous
- Colour
- White, colourless, occasionally pale blue
- Where it forms
- In granites, pegmatites and low-grade metamorphic rocks. It is the sodium end of the plagioclase series.
- Chiefly from
- BrazilItalyVirginia, United States
Safety
No hazard from handling.
Where it comes from
Common and industrially quarried.
Historical use
Named in 1815 from the Latin albus, white. Its significance is structural: it is one of the two fixed points that define the plagioclase series, and therefore one of the two reference compositions against which every plagioclase is measured.
Recorded as history and attributed where possible. That a stone was used for something establishes that people used it, not that it worked.
Worth knowing
Albite matters here for what it anchors. Plagioclase feldspars form a continuous solid solution between albite, which is sodium-rich, and anorthite, which is calcium-rich, and every composition in between exists in nature. There is no gap, no boundary, no point where one becomes the other.
That continuity is the reason the entries that follow have the status they do.
Identity checked against IMA-CNMNC master list, June 2025.