Transition metal monoxides
Unless otherwise noted crystal structure is simple cubic like table salt NaCl.
Typical (with a few exceptions) is 1900°C melting point and Mohs 5.
Monometal monoxides
- ScO - no monoxide? (well its a rare earth anyway)
- TiO - Titanium(II)_oxide - Hongquiite (webminera.com) - 4.96g/ccm | 5.36g/ccm(mineral) - Mohs 5 to 6 - 1,750°C
- VO - Vanadium(II)_oxide - no mineral - 5.758g/ccm - Mohs ?? - 1,789 °C
- CrO - Chromium(II)_oxide - no mineral - only powders by thermodynamic means - 300°C (low!) - Mohs ??
- MnO - Manganese(II)_oxide - Manganosite - 5.364g/ccm - Mohs 5 to 6 - 1,945 °C - water insoluble
- FeO - Iron(II)_oxide - Wüstite - 5.7g/ccm - Mohs 5.0 to 5.5 - 1,377°C - water insoluble
- CoO - Cobalt(II)_oxide - no mineral? - 6.45g/ccm - Mohs ?? - 1,933°C - water insoluble
- NiO - Nickel(II)_oxide - Bunsenite 6.898g/ccm - Mohs 5.5 - 1,955°C - watersolubility negligible
- CuO - Copper(II)_oxide - tenorite 6.5g/ccm - Mohs 3.5 to 4.0 - 1,326 °C - water insoluble - Monoclinic
- ZnO - Zinc_oxide - [1] - 5.64–5.68g/ccm - Mohs 4 - 1,974°C (decomposes) - watersolubility minute - Hexagonal
Dimetal monoxides
- Cu2O - Copper(I)_oxide - Cuprite - 6.14g/ccm - Mohs 3.5 to 4 - 1,232°C - water insoluble - cubic (but...)
There is more metal than oxygen but the material is still transparent. Odd.
Maybe because copper is pretty noble metal?
More scarce silver (in the copper group below copper) does the same but the resulting material has much worse properties.
- Ag2O - Silver_oxide - 7.14g/ccm - Mohs ?? - decompoes ≥ 200 °C - slightly water soluble - cubic (but...)