Hessite
Ag2TeIMA symbol: Hesgrandfathered
Hessite is a sulfide or sulfosalt mineral with the formula Ag2Te, crystallizing in the monoclinic system. It has a Mohs hardness of 2.5-3, typically gray in color, with a metallic luster, a specific gravity of 8.31-8.45. Its streak is black.
Photos




Crystallography
| Crystal system | monoclinic crystal systemWikidata (CC0) |
|---|---|
| Space group | P 1 21/c 1 |
| Cell (Å, °) | a = 8.09, b = 4.48, c = 8.96; α = 90, β = 123.33, γ = 90 |
| Cell volume | 271.326 ų, Z = 4 |
| Axial ratios | 1.8058:1:2.0000calculated from COD 5910144 |
| Source structure | COD 5910144 (Zeitschrift fuer Kristallographie, Kristallgeometrie, Kristallphysik, Kristallchemie (-144,1977), 1959) — 1 of 6 structures |
Powder X-ray diffraction (calculated)
| d (Å) | 2.864 | 2.315 | 2.998 | 2.253 | 2.24 | 2.146 |
|---|---|---|---|---|---|---|
| I/I₀ | 100 | 97.5 | 52.4 | 40.7 | 38.4 | 36.2 |
xrd-v1: CuKa1 1.5406A, 2theta 5-90, top10, Imax=100, no DW/PO. Computed from COD 5910144; idealized occupancies, no preferred orientation.
Physical properties
| Density (calculated) | 8.405 g/cm³calculated from COD 5910144 |
|---|---|
| Hardness (Mohs) | 2.5-3single sourceDana, System of Mineralogy, 6th ed. (1892) |
| Specific gravity | 8.31-8.45 g/cm3corroboratedDana, System of Mineralogy, 6th ed. (1892) |
| Color | graysingle sourceDana, System of Mineralogy, 6th ed. (1892) |
| Streak | blacksingle sourceWikidata (CC0) |
| Luster | metallicsingle sourceDana, System of Mineralogy, 6th ed. (1892) |
Chemistry (calculated)
| Molecular weight | 343.34 g/molcalculated from the IMA formula |
|---|---|
| Composition (wt%) | Ag 62.84%, Te 37.16% |
Classification
| Nickel-Strunz (10th) | 2.BA.60Wikidata (CC0) |
|---|---|
| Nickel-Strunz (9th) | 2.BA.30cWikidata (CC0) |