TANTALUM and COLUMBIUM
Avalon Ventures has been hot on our website with TANTALUM and we thought our readers might want to know more about TANTALUM, so, we've done a little investigating.
TANTALUM and COLUMBIUM are metals of increasing value. They closely resemble each other chemically, but TANTALUM is twice as heavy as COLUMBIUM and is very hard.
OCCURRENCE
COLUMBIUM and TANTALUM are almost always found in either granites or pegmatites or iin sands and gravel near these rocks. COLUMBIUM and TANTALUM are always present together, neither occurs alone.
MINERALS
The three most important minerals are COLUMBITE, TANTALITE and SAMARSKITE.
Columbite:- Columbite and tantalite are much alike and only the trained mineralogist or chemist can tell then apart. Both contain iron, manganese, columbium and tantalum. They are iron-black in color, but their streak is dark red-brown. They are so hard that they cannot be scratched with a knife, unless it contains unusually hard steel. The hardness of columbite is 5.4 to 7; and of tantalite,5.3 to 7.3. A piece of quartz will scratch them. They are much heavier than most minerals, the actual specific gravity of each being 7, nearly two and one-half times as heavy as quartz.
Tantalite:- Tantalite is rare. The pure mineral contains 70 per cent metal, but the percentage in actual minerals is lower.
Samarskite:- Samarskite contains the rare-earth metals and columbium and tantalum |
