Dawsonite
NaAl(CO3)(OH)2IMA symbol: Dwsgrandfathered
Dawsonite is a carbonate or nitrate mineral with the formula NaAl(CO3)(OH)2, crystallizing in the orthorhombic system. It has a Mohs hardness of 3, a calculated density of 2.425 g/cm3. Its streak is white.
Photos
Crystallography
| Crystal system | orthorhombic crystal systemWikidata (CC0) |
|---|---|
| Space group | I 2 c m |
| Cell (Å, °) | a = 6.762, b = 10.428, c = 5.593; α = 90, β = 90, γ = 90 |
| Cell volume | 394.386 ų, Z = 4 |
| Axial ratios | 0.6484:1:0.5363calculated from COD 9012812 |
| Source structure | COD 9012812 (Vestnik Moskovskogo Universiteta Geologiya, 1987) — 1 of 3 structures |
Powder X-ray diffraction (calculated)
| d (Å) | 5.674 | 2.788 | 2.155 | 1.731 | 2.607 | 1.661 |
|---|---|---|---|---|---|---|
| I/I₀ | 100 | 61.2 | 22 | 19.8 | 18.1 | 16.9 |
xrd-v1: CuKa1 1.5406A, 2theta 5-90, top10, Imax=100, no DW/PO. Computed from COD 9012812; idealized occupancies, no preferred orientation.
Physical properties
| Density (calculated) | 2.425 g/cm³calculated from COD 9012812 |
|---|---|
| Hardness (Mohs) | 3single sourceWikidata (CC0) |
| Streak | whitesingle sourceWikidata (CC0) |
Chemistry (calculated)
| Molecular weight | 143.99 g/molcalculated from the IMA formula |
|---|---|
| Composition (wt%) | Na 15.97%, Al 18.74%, C 8.34%, O 55.56%, H 1.4% |
Classification
| Nickel-Strunz (10th) | 5.BB.10Wikidata (CC0) |
|---|---|
| Nickel-Strunz (9th) | 5.BB.10Wikidata (CC0) |