Ramsdellite is a somewhat scarce mineral in the markets, the reason being its rare availability in nature, lack of superior crystals coupled with the difficulty of its identification. It is polymorphic in nature with the fairly widespread mineral pyrolusite.
Derivation of Name
It gets its name from Lewis S. Ramsdell, an American mineralogist who was the first to explain the mineral.
Ramsdellite group is created by pyrolusite’s inversion or by dehydrogenation of Groutite. Crystals are characteristically very big and granular. You can find those are also scarce and tabular. Cleavage is fine, though hardly ever seen except in remarkably big crystals.
It does not find use a as gemstone.
Its fine specimens are prominently found in Germany; Lake Valley, New Mexico, Minnesota, Montana and California, USA and previously, in Czechoslovakia;
Though the chemistry of two minerals Ramsdellite and Pyrolusite is similar, their structures are different. Ramsdellite takes on an orthorhombic structure while Pyrolusite is tetragonal. Akhtenskite, another mineral in this group is still rarer than the two and being hexagonal is a polymorph as well. These three minerals therefore form trimorphic crystals. Ramsdellite is a creation by oxidation of battered manganese minerals, like manganite. It is frequently a small component of "Wad". "Wad" is a mining term used to signify huge ores which are a combination of quite a few manganese oxides like Pyrolusite, Ramsdellite and Psilomelan plus others you may find difficult to distinguish. Manganese is a deliberately precious metal, being an essential component of steel plus other alloys.
Color is gray to black.
Around 3, but varies