So, I took my whole family to Switzerland for a couple of weeks last summer. Both machined and broken surfaces are visible, although the broken ones are much more beautifully crystalline in structure. This piece was broken from a 4N pure sputter target. As for its origin, the original melting company has no idea what it was used for originally and neither do I-massive chunks of pure chromium are pretty scant, the two main examples being electrolytically deposited anodes and sputter targets, of which this is neither. What probably happened was that there wasn't perfect contact between the piece and the crucible, resulting in an arc which flash-vaporized a tiny amount of the copper crucible. Its purity is 3N, so it was partially melted down in a vacuum arc furnace in order to use it as a custom alloy additive- you can see a little bit of copper from the crucible in which is was melted on the top flat face. This is a formerly machined and threaded chromium plug of some sort. Presumably it spins in the wind as you're driving.Ĭr 2O 3 is used as a green pigment in paints and ceramic glazes. This is a chrome-plated plastic propeller designed to be mounted on the back of a trailer hitch that is not currently being used to pull a trailer. This process, called electrowinning, is how high-purity chromium is obtained from solution.Ĭlick here to buy a book, photographic periodic table poster, card deck, or 3D print based on the images you see here! Many shiny things are chrome-plated these chips show the result if you keep plating until a thick slab is built up. Chromite, chromium's primary ore, is used to make molds for the firing of bricks because of its high melting point, moderate thermal expansion and stable crystal structure.Įstimated Crustal Abundance: 1.Pictures, stories, and facts about the element Chromium in the Periodic Table H Chromium compounds are also used to anodize aluminum, a process which coats aluminum with a thick, protective layer of oxide. Potassium dichromate (K 2Cr 2O 7) is used in the tanning of leather while other chromium compounds are used as mordants, materials which permanently fix dyes to fabrics. Rubies and emeralds also owe their colors to chromium compounds.
Chromic oxide (Cr 2O 3), also known as chrome green, is the ninth most abundant compound in the earth's crust and is a widely used green pigment. Lead chromate (PbCrO 4), also known as chrome yellow, has been used as a yellow pigment in paints. Other chromium-steel alloys are used to make armor plate, safes, ball bearings and cutting tools.Ĭhromium forms many colorful compounds that have industrial uses. Chromium is added to steel to harden it and to form stainless steel, a steel alloy that contains at least 10% chromium. Chromium can be polished to form a very shiny surface and is often plated to other metals to form a protective and attractive covering. Today, chromium is primarily obtained by heating the mineral chromite (FeCr 2O 4) in the presence of aluminum or silicon.Ĭhromium is a blue-white metal that is hard, brittle and very corrosion resistant. Although he believed a method for isolating chromium didn't yet exist, Vauquelin was pleasantly surprised in 1798 to discover that he was able to obtain metallic chromium by simply heating chromium oxide in a charcoal oven. He produced chromium oxide (CrO 3) by mixing crocoite with hydrochloric acid (HCl). Chromium was discovered by Louis-Nicholas Vauquelin while experimenting with a material known as Siberian red lead, also known as the mineral crocoite (PbCrO 4), in 1797.
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