1) Calcium mineral
Found on
https://www.crosswordclues.com/clue/nenadkevichite
Nenadkevichite is a rare silicate mineral containing niobium with formula: (Na,Ca)(Nb,Ti)Si2O7·2H2O. It forms brown to yellow to rose colored orthorhombic dipyramidal crystals with a dull to earthy luster. It has a Mohs hardness of 5 and a specific gravity of 2.86. It was first reported in 1955 from a nepheline syenite pegmatite in the Kola Penin...
Found on
http://en.wikipedia.org/wiki/Nenadkevichite
No exact match found.
