Overview Area For Mineral Collection
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Galena is quite a rare mineral find in Lockport dolomite.
Chemically, galena is lead sulfide and naturally occurs as cubes, cubes with the corners truncated and when the truncation is complete, as octahedrons.
It has strong cleavage on three perpendicular planes and breaks into rectangular
blocks.
Galena is one of the few minerals that can be used to build simple crystal radio receivers
as was done in the early days of broadcast radio.
Galena is the principal ore of lead where it occurs in abundance. As it is
normally insoluble, however it will dissolve in hot hydrochloric acid (giving off the odor
of "rotten eggs" and in strong nitric acid (producing flakes of sulfur and the
white precipitate of lead sulfate).
This specimen of Silicon Carbide in the Marv Hess collection was given to him some years ago by a friend who worked for the Carborundum Corporation located in Niagara Falls.
The image doesn't do justice to the beauty of this large specimen with its shiny black iridescent crystals. It is a specimen which must be handled with great care as the thin bladelike crystals will easily cut ones skin.
Silicon carbide is made in huge electric furnaces by passing a massive
current through a sand (silicon dioxide) coke (carbon) mixture with wood chips and other
secret ingredients. Locating in Niagara Falls along with other electricity hungry
chemical industries, (like Hooker Chemical electrolizing salt solution to make chlorine
and caustic soda) was a natural at the dawn of the 20th century with abundant cheap direct
current power supplied by the Schoellkopf generating station within view of the falls.
Silicon carbide or "Carborundum" is made for its hardness and abrasive qualities
and is incorporated into grinding wheels and sharpening stones. It ranks with
corundum (aluminum oxide) in hardness and with brittle fracture, retains sharp cutting
edges even as it wears down. Silicon and carbon have quite similar chemical
properties forming bonds in a tetrahedral geometry. Carbon bonded three
dimensionally with tetrahedral bonding is diamond, which is about as hard a material as
can be found. Silicon carbide is not far behind. A bit of the history:
"It started over 100 years ago. A struggling scientist, once
employed by Thomas Edison, dreamed of becoming wealthy.
What better way to riches, he reasoned, than by making
artificial diamonds?
The determined young man attached one lead from a dynamo
to a discarded plumber's bowl, filled the bowl with clay and
powdered coke, inserted the other lead into the mix and threw
the switch. Nothing seemed to happen. He was disappointed
until he noticed a few bright specks on the end of the leads.
When he drew one lead across a pane of glass, it cut like a
diamond.
This young scientist, Dr. Edward Goodrich Acheson, had
invented silicon carbide (SiC), the first man-made abrasive
and substance hard enough to cut glass. Acheson's discovery
became Carborundum, the trademark for silicon carbide and
the name given to the company he started.
For now, this is the extent of our mineral galleries.
Additional galleries are under construction.
Please come back and visit us again.
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