Ankangite (incl.)
Ankangite is named for its discovery within the Ankang Prefecture, Shaanxi Province, China (at the Shiti Mine, Hanbin District). Ankangite is a rare Barium Titanium Vanadium Chromium Oxide mineral that can be found as very interesting and radiating that is attractive “urchin searching” inclusions in Quartz crystals. Quartz crystals with these rare, radiating Ankangite inclusions happen found at Morro Hill near the town of Tomás Gonzaga, Curvelo, Minas Gerais, Brazil. All other locations produce lustrous, black, prismatic Ankangite crystals that have grown on the areas of host Quartz not as inclusions within the Quartz. Ankangite was discovered in 1986 but was discredited being a mineral that is distinct in 2012 by the IMA as it corresponds to an H2O-free variety of Mannardite.
Locations for Ankangite: at the kind locality at the Shiti Mine, Hanbin District, Ankang Prefecture, Shaanxi Province, China. In Brazil as beautiful inclusions in Quartz crystals at Morro Hill near the town of Tomás Gonzaga, Curvelo, Minas Gerais. In Italy at Monte Arsiccio Mine, Sant’Anna di Stazzema, Stazzema, Apuan Alps, Lucca Province, Tuscany. In Russia at the Pereval Marble Quarry, Slyudyanka (Sludyanka), Lake Baikal area, Irkutskaya Oblast’, Prebaikalia (Pribaikal’e), Eastern-Siberian Region; as well as Vuonnemiok River Valley, Khibiny Massif, Kola Peninsula, Murmanskaja Oblast’, Northern Region, Russia.
| Chemical Formula: | Ba(Ti,V3+,Cr3+)8O16 |
| Barium Titanium Vanadium Chromium Oxide | |
| Molecular Weight: | 803.05 gm |
| Composition: | Barium | 18.81 % | Ba | 21.00 % | BaO |
| Titanium | 32.79 % | Ti | 54.71 % | TiO2 | |
| Vanadium | 15.22 % | V | 22.40 % | V2O3 | |
| Chromium | 1.29 % | Cr | 1.89 % | Cr2O3 | |
| Oxygen | 31.88 % | O | |||
| 100.00 % | 100.00 % | = TOTAL OXIDE |
| Crystallography: | Tetragonal – Dipyramidal |
| Crystal Habit: | Crystals, euhedral to subhedral, prismatic, with {100} and {110}, to 1 mm. |
| Twinning: | None |
| Cleavage: | Interrupted elongation, possibly a parting |
| Fracture: | Irregular/Uneven |
| Tenacity: | Brittle |
| Moh’s Hardness: | Vickers: VHN100=874 kg/mm2 |
| Density: | 4.44 (g/cm3) |
| Luminescence: | None |
| Radioactivity: | Not Radioactive |
| Color: | Black; in reflected light, light rose-reddish gray |
| Transparency: | Opaque |
| Luster: | Vitreous to adamantine |
| Bireflectance: | R1–R2: (589) 12.8–20.1 |
| Birefringence: | n/a |
| Dispersion: | n/a |
| Pleochroism: | O = pinkish grey, E = light pink, Orientation: E = c |
| Anisotropism: | Bireflectance: Weak to distinct. Color in reflected light, light rose-reddish gray. |
