|
|
|
|
|
|
|
|
|
|
Shiny! Chromium is just incredibly shiny, and many of the shiny things in our world are shiny because of chromium. It's plated on car bumpers, plastic toys, and just about anything else you can think of. As a shiny element, chromium is almost unbeatable: It's cheap, easy to electroplate, does not corrode, and of course, it's very shiny. Silver is shiny too, but it tarnishes quickly. Platinum is shiny and doesn't tarnish, but it's expensive. Rhodium is used for plating jewelry, but I'm not sure why, because it doesn't look any shinier to me. Maybe it's just because too many chemical engineers got slapped after bringing their wives an experimental chrome plated ring.
While everyone has seen chromium plated objects, bulk solid chromium is very uncommon. There's just no reason to want something made out of solid chromium, because usually a few microns on the surface is plenty: Solid chromium wouldn't be any shinier, and it would be a lot more expensive. In fact even though thousands of tons of chromium are mined and plated onto products every year, almost none of it ever exists as lumps of solid chromium: It is turned into chromic acid as it is extracted from the ore, then shipped to electroplating companies in that form. There's just no reason to ever turn it into metal before it's plated onto something like a car bumper. This is a pity, because it means finding some unused scrap chunk of chromium to use as an element sample is almost impossible.
Did I mention it's very shiny?
|
|
| |
|
|
|
|
|
 Small crystal lumps 99.9%.
Kindly donated by David Franco, who sent many elements after seeing the slashdot discussion. Very attractive little bits of metal!
Here is a joke about Chromium, one of the few known element jokes:This guy goes into his dentist's office, because something is wrong with his mouth. After a brief examination, the dentist exclaims, "Holy Smoke! That plate I installed in your mouth about six months ago has nearly completely corroded! What on earth have you been eating?"
"Well... the only thing I can think of is this... my wife made me some asparagus about four months ago with this stuff on it... Hollandaise sauce she called it... and doctor, I'm talkin' DELICIOUS! I've never tasted anything like it, and ever since then I've been putting it on everything... meat, fish, toast, vegetables.. you name it!"
"That's probably it," replied the dentist "Hollandaise sauce is made with lemon juice, which is acidic and highly corrosive. It seems as thought I'll have to install a new plate, but made out of chrome this time."
"Why chrome?" the man asked.
"Well, everyone knows that there's no plate like chrome for the Hollandaise!"
Source: David Franco
Contributor: David Franco
Acquired: 17 May, 2002
Price: Donated
Size: 0.3"
Purity: 99.9%
|
|
|
|
|
|
|
Electroplated foil.
This is a thin foil of chromium electroplated on nickel foil, from the Flex-n-Gate manufacturing plant in Urbana, Illinois.
My van had broken down (bad battery) and I was waiting at Peter B's repair shop for them to put in a new one. I noticed I was sitting with nothing to do just across the street from what bills itself as the largest manufacturer of automotive bumpers in the country, Flex-n-Gate. I immediately thought CHROMIUM and took a walk over to their front office.
The receptionist seemed a bit confused about who she should direct me to, but finally went in back to find an engineer: Presumably she thought he would at least know what I was talking about.
The engineer, Douglas Suits, was very understanding, and I showed him some photographs of the Periodic Table on my PowerBook. He said he would check around for some samples, and later that day I went back to pick up an envelope containing this flake for chromium and two very nice chunks of nickel (see).
Unfortunately, while they receive nickel in metallic form, chromium arrives in the form of chromic acid because that is more convenient for electroplating. So while they probably have more chromium in one place than almost any other place on earth, he was unable to give me any. They have so much nickel they actually have to keep a guard on it because of its value, but presumably no one wants to steal chromic acid!
He explained that bumpers are actually not primarily plated with chromium but rather with nickel. They electroplate 0.0010" of semi-bright nickel, 0.0003" of bright nickel, and only 0.000000066" of chromium onto the base of steel.
Source: Flex-n-Gate, Inc
Contributor: Flex-n-Gate, Inc
Acquired: 25 April, 2002
Price: Donated
Size: 0.3"
Purity: >99%
|
|
|
|
|
|
|
Granular powder.
This is a nice dense granular powder of metallic chromium. Weighs more than you'd expect for a powder.
Source: Mark Rollog
Contributor: Theodore Gray
Acquired: 20 July, 2002
Price: $8
Size: 0.01"
Purity: >99%
|
|
|
|
|
|
|
Vapor grown crystals.
These small crystals came with a helpful little card, which states as follows: "These crystals are produced in a high vacuum chamber. The chamber is heated to the point where the metal vaporizes and sublimates onto a glass substrate."
Source: SoCal (Nevada), Inc
Contributor: Ed Pegg Jr
Acquired: 5 August, 2002
Price: $10
Size: 0.1"
Purity: >99%
|
|
|
|
|
|
|
|
|
|
|
|
|
Sample from the Everest Element Set.
Up until the early 1990's a company in Russia sold a periodic table collection with element samples. At some point their American distributor sold off the remaining stock to a man who is now selling them on eBay. The samples (excepted gasses) weight about 0.25 grams each, and the whole set comes in a very nice wooden box with a printed periodic table in the lid.
To learn more about the set you can visit my page about element collecting for a general description and information about how to buy one, or you can see photographs of all the samples from the set displayed on my website in a periodic table layout or with bigger pictures in numerical order.
Source: Rob Accurso
Contributor: Rob Accurso
Acquired: 7 February, 2003
Price: Donated
Size: 0.2"
Purity: >99%
|
|
|
|
|
|
|
|
|
|
Chromium Petrified Wood.
The tag that came with sample reads as follows:Jurassic, Arizona USA
This wood has been minerally replaced with Chromium giving it a green color. Very little of this wood has ever been found, making it very rare. This wood is a natural hygrometer, when dry it becomes a very light pale green and when wet or exposed to humidity it turns a deep green.
Source: Fossil Image Ltd.
Contributor: Theodore Gray
Acquired: 29 March, 2003
Price: $15
Size: 2"
Composition: Cr
|
|
|
|
|
|
