Mellite
Al2C6(COO)6·16H2OIMA symbol: Melgrandfathered
Mellite is an organic mineral with the formula Al2C6(COO)6·16H2O, crystallizing in the tetragonal system. It has a Mohs hardness of 2-2.5, typically white, brown, red or yellow in color, with a resinous or vitreous luster, a specific gravity of 1.55-1.65. Its streak is white.
Photos
Crystallography
| Crystal system | tetragonal crystal systemWikidata (CC0) |
|---|---|
| Space group | I 41/a c d :2 |
| Cell (Å, °) | a = 15.553, b = 15.553, c = 23.11; α = 90, β = 90, γ = 90 |
| Cell volume | 5590.21 ų, Z = 16 |
| Axial ratios | 1.0000:1:1.4859calculated from COD 9012197 |
| Source structure | COD 9012197 (Journal of Solid State Chemistry, 1991) |
Powder X-ray diffraction (calculated)
| d (Å) | 7.966 | 4.24 | 5.777 | 3.388 | 5.162 | 3.452 |
|---|---|---|---|---|---|---|
| I/I₀ | 100 | 87.4 | 56.2 | 43.2 | 40.3 | 35.5 |
xrd-v1: CuKa1 1.5406A, 2theta 5-90, top10, Imax=100, no DW/PO. Computed from COD 9012197; idealized occupancies, no preferred orientation.
Physical properties
| Density (calculated) | 1.612 g/cm³calculated from COD 9012197 |
|---|---|
| Hardness (Mohs) | 2-2.5single sourceDana, System of Mineralogy, 6th ed. (1892) |
| Specific gravity | 1.55-1.65 g/cm3corroboratedDana, System of Mineralogy, 6th ed. (1892) |
| Color | brown, red, white, yellowsingle sourceDana, System of Mineralogy, 6th ed. (1892) |
| Streak | whitesingle sourceWikidata (CC0) whitesingle sourceDana, System of Mineralogy, 6th ed. (1892) |
| Luster | resinous, vitreoussingle sourceDana, System of Mineralogy, 6th ed. (1892) |
Chemistry (calculated)
| Molecular weight | 678.33 g/molcalculated from the IMA formula |
|---|---|
| Composition (wt%) | Al 7.96%, C 21.25%, O 66.04%, H 4.75% |
Classification
| Nickel-Strunz (10th) | 10.AC.05Wikidata (CC0) |
|---|---|
| Nickel-Strunz (9th) | 10.AC.05Wikidata (CC0) |