Properties of Lepidolite

Lepidolite is a mineral that belongs to the mica group. It is a lithium-rich mineral and is typically found in granite pegmatites, which are coarse-grained igneous rocks. Lepidolite is known for its striking lilac or lavender color, which is often caused by the presence of manganese.

Image of lepidolite mineral
Credit: Eurico Zimbres, via Wikimedia Commons

The following table provides a comprehensive list of lepidolite properties in both SI and US customary/Imperial units at normal temperature and pressure (NTP).

Note: click on the icon to switch between Metric and Imperial units.

Table of Lepidolite Properties
Physical Properties
Metric
Chemical FormulaK(Li,Al)3(Si,Al)4O10(F,OH)2
Molar Mass386.31 g/mol
Crystal SystemMonoclinic
Mohs Hardness2.5 - 3
Density2800 - 2900 kg/m3
ColorPale lilac blue, light red, colorless, or gray
DiaphaneityTranslucent
LusterVitreous, pearly
Cleavage(001) perfect
FractureUneven
StreakWhite

Note: unless stated otherwise, all values are taken at room temperature (approximately 20°C or 68°F) and 1 atm pressure. (1 atm = 101,325 Pa)

Related Pages
References: 1) Cardarelli, François. Materials Handbook: A Concise Desktop Reference. Switzerland: Springer International Publishing, 2018. 2) CRC Handbook of Chemistry and Physics, 97th Edition. United Kingdom: CRC Press, 2016-2017.