Pitchblende is a Uranium ore usually found as a component of granite rock. Abundant in the Canadian Great Lakes, the Czech Republic, Australia, and South Africa, pitchblende is also known to exist in a few US mines, the largest of which is in Marysvale, Utah. As with many minerals, there is always the possibility that undiscovered deposits remain to be found.
The Uranium in pitchblende is mingled with other radioactive metals such as radium, and also lead, and thorium. Pitchblende's appearance can be described as "botryoidal", and I'm told it exhibits a certain dull lustre. It is an opaque, radioactive, and usually grayish-black or dark brown mineral (rock).
It was in their stockpiles of pitchblende that the famous French scientists Marie and Pierre Curie discovered radium and polonium (two other radioactive metals present in pitchblende) in 1898. They were prompted to look for new radioactive metals in pitchblende because over 100 years before them, while exploring the properties of pitchblende from the German town of Joachimsthal, one Martin Heinrich Klaproth, (the namesake of the dreaded Klaproth bot), had discovered Uranium (or, rather, a Uranium compound, but 'close enough', as they say), which he named in honor of the newly-discovered planet Uranus.
Klaproth's contemporaries used the Uranium dioxide (or
uraninite, i.e., UO2) he'd discovered in pitchblende to glaze ceramic dishware because they liked the way the dishes glowed and sparkled, not realizing that this was a result of
radioactivity. In fact, the practice of
glazing with Uranium was only recently abandoned as the standard, and some mildly-radioactive ceramic dishes survive today in the
cupboards of the unsuspecting. The
EPA does not see these dishes as "a serious
health risk" but advises that they "may nevertheless be retired from use as a
prudent avoidance measure." Small, naturally-occurring deposits of pitchblende are implicated as one factor in the buildup of dangerous
radon gas in basements and homes.
Pitchblende's historic pinnacle came in World War II, when its ability to supply relatively large amounts of Uranium became important to the development of the atomic bomb.
Update 30 May 04: 0336 EDT / 0736 UTC
According to
dem_bones, our
Klaproth bot derives his name not from
Martin Heinrich Klaproth, but from from a character in
The Sandman by
Neil Gaiman. This fact notwithstanding, I would speculate that
Gaiman may have been inspired to name his
Klaproth character after the famous discoverer of Uranium.
In any case, Klaproth is a fitting name for one with the task of destruction.
Sources
29 May 2004
http://nautilus.fis.uc.pt/st2.5/scenes-e/biog/b0023.html
http://www.ellesmerecoin.com/articles/205.html
http://education.yahoo.com/reference/encyclopedia/entry?id=37606
http://www.epa.gov/radiation/radionuclides/uranium.htm
http://linc.cs.vt.edu/schools/bms/suzan2/pitch.htm
http://www.gardenbanter.co.uk/archive/41/2004/04/3/58977