1) Potassium mineral 2) Sodium mineral
Found on
https://www.crosswordclues.com/clue/birnessite
Birnessite (Na0.3Ca0.1K0.1)(Mn4+,Mn3+)2O4 · 1.5 H2O is an oxide mineral of manganese along with calcium, potassium and sodium. It has a dark brown to black color with a submetallic luster. It is also very soft, with a Mohs hardness of 1.5. Birnessite is formed by precipitation in lakes, oceans and groundwater and is a major component of desert va...
Found on
http://en.wikipedia.org/wiki/Birnessite
No exact match found.
