Brucite
Mg(OH)2IMA symbol: Brcgrandfathered
Brucite is an oxide or hydroxide mineral with the formula Mg(OH)2, crystallizing in the trigonal system. It has a Mohs hardness of 2-5, typically white, blue, gray or green in color, with a pearly or vitreous luster, a specific gravity of 2.38-2.4. Its streak is white; cleavage is eminent.
Photos
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Crystallography
| Crystal system | trigonal crystal systemWikidata (CC0) |
|---|---|
| Space group | P -3 m 1 |
| Cell (Å, °) | a = 3.142, b = 3.142, c = 4.766; α = 90, β = 90, γ = 120 |
| Cell volume | 40.7 ų, Z = 1 |
| Axial ratios | 1.0000:1:1.5169calculated from COD 1000054 |
| Source structure | COD 1000054 (Neues Jahrbuch fuer Mineralogie. Monatshefte (Band=Jahr) (1950-), 1967) — 1 of 15 structures |
Powder X-ray diffraction (calculated)
| d (Å) | 2.363 | 4.766 | 1.793 | 1.571 | 1.372 | 1.492 |
|---|---|---|---|---|---|---|
| I/I₀ | 100 | 64.2 | 46.6 | 28.4 | 16.1 | 13.4 |
xrd-v1: CuKa1 1.5406A, 2theta 5-90, top10, Imax=100, no DW/PO. Computed from COD 1000054; idealized occupancies, no preferred orientation.
Physical properties
| Density (calculated) | 2.377 g/cm³calculated from COD 1000054 |
|---|---|
| Hardness (Mohs) | 2-5single sourceDana, System of Mineralogy, 6th ed. (1892) |
| Specific gravity | 2.38-2.4 g/cm3corroboratedDana, System of Mineralogy, 6th ed. (1892) |
| Color | blue, gray, green, whitesingle sourceDana, System of Mineralogy, 6th ed. (1892) |
| Streak | whitesingle sourceWikidata (CC0) |
| Luster | pearly, vitreous, waxysingle sourceDana, System of Mineralogy, 6th ed. (1892) |
| Cleavage | eminentsingle sourceDana, System of Mineralogy, 6th ed. (1892) |
Chemistry (calculated)
| Molecular weight | 58.32 g/molcalculated from the IMA formula |
|---|---|
| Composition (wt%) | Mg 41.68%, O 54.87%, H 3.46% |
Classification
| Nickel-Strunz (10th) | 4.FE.05Wikidata (CC0) |
|---|---|
| Nickel-Strunz (9th) | 4.FE.05Wikidata (CC0) |