NATURALLY RADIOACTIVE MINERALS
Among the representative list of minerals that are radioactive,
a number are listed below. These are concentrated enough to be of
interest to mining companies. In addition, many areas have dissolved
radioactive salts in sub-surface water greatly in excess of environmentally
safe limits and must be treated and filtered to specifically remove
this hazard.
In some areas of the USA, mining
companies use chemical solutions pumped into the ground to wash
out uranium salts. In the USA alone, a quarter of the drinking
water supplies contain 2000 picocuries per liter of radon gas. Five
percent of the domestic water supplies have radon levels above 10,000
picocuries per liter. Water pumped from private wells should be
tested for radioactivity.
In the process of oil exploration
and recovery, uranium and radium bearing formations are drilled
through and the fluids used to cool and lubricate the drilling bits
can be contaminated. This drilling fluid or "mud" often
was left to dry in an open pit. Insoluble radium compounds can build
up or "plate up" to alarming levels on the pipe.
Over three billion cubic feet
of mine wastes from the uranium and thorium extraction still await
proper disposal. These waste heaps remain about 85% as radioactive
as the original ore from the radioactive breakdown products of uranium
and thorium. Thousands of tons of ore were transported for processing
to areas near major population centers, like Niagara, NY, Salt Lake
City, Utah, Cincinnati, Ohio and Chicago, IL. In some cases, the
mining wastes were used to make concrete for buildings and roads.
These m ounds of milling wastes are persistent sources of soluble
radium salts and radon gas.
Some radioactive minerals collected
are:
Autunite, Ca(UO2)2 (PO4)2 .
10-12 H2O, Hydrated calcium uranium phosphate formed as mixed yellow
or green tetragonal platelets that fluoresce bright yellow-green.
Cornwall,England; Mount Pine, North Carolina; Western Colorado;
Marysville, Utah; near Spokane, Washington. Mount Painter, Australia;
Autun, France. Novacekite, Mg rich form of Autunite.
Brannerite, UTi2O6, A uranium
titanate with rare earth and iron oxides varying the composition
in rounded black or brown pebbles and triclinic crystals. Found
in W. Custer County, Idaho; Elliot Lake District, Ontario,Canada;
Transvaal, S. Africa.
Carnotite, K2(UO2)2(VO4)2
. 3H2O, A potassium uranium vanadate in sandy or powdery bright
yellow masses. Found in Arizona, Colorado, Nevada, New Mexico, Pennsylvania,
Utah in USA; Elliot Lake, Ontario, Canada; Radium Hill, Australia;
Katanga; Mexico.
Monazite, (Ce, La, Yt, Th)(PO4),
Mixed rare earth and thorium phosphates in white, yellow to brown
monoclinic prismatic waxy looking crystals. Found in granite and
gneiss worldwide.
Thorianite, ThO2, Thorium dioxide
in dark grey to black cubic crystals. Found in Easton, Pennsyvania;
Betroka, Madagascar; Balagoda, Sri Lanka. Uranothoranite is a thorium
rich mineral found with thoranite.
Thorite, ThSiO4, Thorium silicate
in yellow-brown to black, tetragonal or pyramidal crystals or masses.
Found in Champlain, New York; Esmark, Norway.
Torbernite, Cu(UO2)2(PO4)2 .
12H2O, A copper uranium phosphate in greenish tabular crystals or
scales. Found in Cornwall, England; New Mexico, Hannibal Mine, S.
Dakota; the La Sal Mountains of Utah, USA; Mount Painter, Australia;
Schneeberg, Germany.
Tyuyamunite, Ca(UO2)2(VO4)2
. 10H2O, A hydrous calcium uranium vanadate in greenish yellow scales
or masses. Found in Montrose County, Colorado, Garfield County,
Utah, USA; Turkestan, USSR.
Uraninite, UO2, Uranium dioxide
in greenish or grayish brown or black cubic crystals or masses also
known as pitchblende or cleveite.
Uranophane or uranotile
, Ca(UO2)2(Si2O7 . 6H2O, A hydrated calcium uranium silicate in
yellow needle-like crystals or crystaline masses. Found in Mitchell
County, N. Carolina, USA; Silesia, Czechoslovakia; Saxony, Germany.
Zircon, the semi-precious
stone, can be radioactive, even to the extent that it changes crystal
structure over a long period of time.