MINERAL PROPERTIES: RADIOACTIVITY
Radioactivity is an attribute of minerals that contain radioactive elements. Radioactive elements are elements
that contain disintegrating nuclei,
emitting alpha rays, beta rays, and gamma rays. Uranium and thorium are the
best known radioactive elements. Minerals that contain these elements in their chemical structure
will be radioactive.
Radioactive minerals are unstable, meaning the
elements in their structure continually break down. This destroys the mineral's crystal lattice, causing it lose its
crystal shape. When this happens, its crystal edges become rounded, and the mineral
eventually becomes amorphous. During
this process, it also becomes opaque and develops a pitchy luster. Minerals that have gone
through this breakdown process are known as metamict. This process is very slow,
and one need not worry about a crystallized radioactive mineral breaking down in his
Radioactive minerals can be identified with special
instruments that detect radiation. The
device used to measure this is the Geiger counter. Electric charges develop in a
Geiger counter when it is placed near radioactive material; this can measure the presence
and intensity of radiation. Geiger counters are normally used by scientists and
specialists, but collectors may also obtain inexpensive Geiger counters.
Radioactive minerals are often similar in appearance,
and it may be difficult to distinguish them without x-ray analysis. There are, generally
speaking, two appearances of radioactive minerals:
- Those that are bright neon yellow or green.
- Those with the typical metamict appearance: opaque and dull with a
pitchy luster and rounded crystal edges (or amorphous).
Radioactive minerals emit various forms of radiation,
including harmful gamma rays. Many
collectors avoid radioactive minerals because of their hazards, but if proper safeguards
and precautions are followed, the dangers are minimized and even amateur collectors can
collect without concern.
Some guidelines for radioactive minerals:
- Do not collect specimens larger than 2 inches (about 4 cm),
unless they will be properly shielded with special x-ray shielding.
- Handle specimens as little as possible; if they are touched
wash hands with soap.
- Never store specimens, even the smallest of size, in an
- Keep all specimens out of children's reach.
- Never eat, drink, smoke, or sleep near a radioactive mineral.
- Label all radioactive specimens as radioactive.
Some mineral collectors specialize in radioactive minerals.
They are very careful and take all necessary precautions. It is best not to collect
radioactive minerals unless one is fully knowledgeable about these facts and obeys them.