Properties of Wollastonite

Wollastonite is a naturally occurring calcium silicate mineral with the chemical formula (CaSiO3). It belongs to the pyroxenoid group of minerals and is characterized by its needle-like or fibrous crystal structure.

Image of wollastonite mineral
Credit: Piotr Sosnowski, CC BY-SA 4.0, via Wikimedia Commons

The following table provides a comprehensive list of wollastonite 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 Wollastonite Properties
Physical Properties
Metric
Chemical FormulaCaSiO3
Crystal SystemTriclinic
Mohs Hardness4.5 - 5
Density3100 kg/m3
ColorWhite
DiaphaneityTransparent to translucent
LusterSilky
Cleavage(100) perfect, (001) distinct
FractureUneven
StreakWhite
Thermal PropertiesMetric
Melting Point1540 °C

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.