Properties of Spinel

Spinel is a mineral that belongs to the spinel group, which encompasses a family of minerals with similar crystal structures. The most common type of spinel is magnesium aluminum oxide (MgAl2O4), but it can also contain other elements, leading to variations in color.

Image of spinel mineral
Credit: Rob Lavinsky, iRocks.com - CC-BY-SA-3.0, via Wikimedia Commons

The following table provides a comprehensive list of spinel 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 Spinel Properties
Physical Properties
Metric
Chemical FormulaMgAl2O4
Molar Mass142.266 g/mol
Crystal SystemCubic
Mohs Hardness7.5 - 8
Density3560 kg/m3
ColorColorless, red, blue, green, or brown
DiaphaneityTransparent, translucent, opaque
LusterVitreous (glassy)
Cleavage{111} poor
FractureConchoidal or uneven
StreakGrayish white
Thermal PropertiesMetric
Melting Point2130 °C
Coefficient of Thermal Expansion (αL)7.45×10-6 1/°C
Optical PropertiesMetric
Refractive Index (nD)1.719

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.