Mineral Factbook

Periclase

MgOIMA symbol: Pergrandfathered

Periclase is an oxide or hydroxide mineral with the formula MgO, crystallizing in the cubic system. It has a Mohs hardness of 6, typically colorless, gray or green in color, a specific gravity of 3.674. Its streak is white; cleavage is perfect.

Photos

Periclase specimen photo
Pacific Museum of Earth from Canada · CC BY-SA 2.0 · Commons
Periclase specimen photo
Mai Seppel · CC BY-SA 4.0 · Commons
Periclase specimen photo
Rafał, J., Biljana, K., Georgia, C. et al. · CC BY 4.0 · Commons
Periclase specimen photo
Rafał, J., Biljana, K., Georgia, C. et al. · CC BY 4.0 · Commons

Crystallography

Crystal systemcubic crystal systemWikidata (CC0)
Space groupF m -3 m
Cell (Å, °)a = 4.2331, b = 4.2331, c = 4.2331; α = 90, β = 90, γ = 90
Cell volume75.853 ų, Z = 4
Axial ratios1.0000:1:1.0000calculated from COD 9016818
Source structureCOD 9016818 (American Mineralogist, 2012) — 1 of 283 structures

Powder X-ray diffraction (calculated)

2θ (degrees, Cu Kα1)I/I₀ (max 100)
d (Å)2.1171.4972.4441.2221.276
I/I₀10056.220.81711

xrd-v1: CuKa1 1.5406A, 2theta 5-90, top10, Imax=100, no DW/PO. Computed from COD 9016818; idealized occupancies, no preferred orientation.

Physical properties

Density (calculated)3.999 g/cm³calculated from COD 9016818
Hardness (Mohs)
6Dana, System of Mineralogy, 6th ed. (1892)
Specific gravity
3.674 g/cm3single sourceDana, System of Mineralogy, 6th ed. (1892)
Color
colorless, gray, greensingle sourceDana, System of Mineralogy, 6th ed. (1892)
Streak
whitesingle sourceWikidata (CC0)
Cleavage
perfectDana, System of Mineralogy, 6th ed. (1892)

Chemistry (calculated)

Molecular weight40.3 g/molcalculated from the IMA formula
Composition (wt%)Mg 60.3%, O 39.7%

Classification

Nickel-Strunz (10th)4.AB.25Wikidata (CC0)
Nickel-Strunz (9th)4.AB.25Wikidata (CC0)