Prussian blue is a blue pigment used in paints and formerly in blueprints. It has several different chemical names, these being iron(III) ferrocyanide, ferric ferrocyanide, iron(III) hexacyanoferrate(II), and ferric hexacyanoferrate. Blue (from Old High German blao shining) is one of the three primary additive colors; blue light has the shortest wavelength range (about 420-490 nm) of the three primary colors. ... In biology, pigment is any material resulting in color in plant or animal cells which is the result of selective absorption. ... For information on the U.S. borough, see Paint, Pennsylvania. ... Modern blueprint of the French galleon La Belle. ... A cyanide is any chemical compound that contains the group C≡N, with the carbon atom triple bonded to the nitrogen atom. ...

The chemical formula is Fe₄[Fe(CN)₆]₃. A chemical formula (also called molecular formula) is a concise way of expressing information about the atoms that constitute a particular chemical compound. ...

Prussian blue can also act as a chelating agent, and is used as a treatment for heavy metals poisoning. In particular, it is used for patients who have ingested radioactive caesium or thallium (also non-radioactive thallium). Chelation (from Greek, claw like) describes the reversible binding of an organic ligand, the chelator or chelating agent, to a metal ion, forming a metal complex, the chelate. ... For other meanings, see heavy metal The term heavy metal may have various more general or more specific meanings. ... Radioactive decay is the set of various processes by which unstable atomic nuclei (nuclides) emit subatomic particles. ... General Name, Symbol, Number Caesium, Cs, 55 Series Alkali metals Group, Period, Block 1(IA), 6, s Density, Hardness 1879 kg/m3, 0. ... General Name, Symbol, Number Thallium, Tl, 81 Chemical series Poor metals Group, Period, Block 13 (IIIA), 6, p Density, Hardness 11. ...

The intense blue color of Prussian Blue is caused by the transfer of electrons from one iron atom to another within the molecule. 680 nm (red) light is absorbed, causing an electron to transfer from an Fe(II) atom to a neighboring Fe(III) atom. The reflected light looks blue as a result. Properties The electron is a subatomic particle. ... Properties For alternative meanings see atom (disambiguation). ... In science, a molecule is the smallest particle of a pure chemical substance that still retains its chemical composition and properties. ... Red is a color at the lowest frequencies of light discernible by the human eye. ...

As engineer's blue it is mixed with an oily material, and rubbed onto a metallic surface. This is then rubbed with another surface, and the removal of the pigment indicates the position of high-spots. Thus it can be used to indicate the flatness of a surface or the trueness of a bearing assembly. The intuitive idea of flatness is important in several fields. ... A bearing is a component used to reduce friction in a machine. ...

Joseph Whitworth invented the first practical method of making and polishing accurate flat surfaces in 1830. This used engineer's blue and three trial surfaces. This led to an explosion of development of precision instruments using his flat surfaces as a basis for further construction of precise shapes. Sir Joseph Whitworth, Baronet (December 21, 1803 - January 22, 1887) was an English engineer and entrepreneur. ... 1830 was a common year starting on Friday (see link for calendar). ...

Despite the presence of the cyanide ion, Prussian Blue, like other ferro- and ferri-cyanides, is not especially toxic due to the strong binding between the cyanide and ferrous or ferric (iron) ions. However, treatment with acids can liberate the cyanide in the form of hydrogen cyanide, which is extremely toxic. A cyanide is any chemical compound that contains the group C≡N, with the carbon atom triple bonded to the nitrogen atom. ... An ion is an elementary particle or system of elementary particles with a net electric charge. ... An acid (often represented by the generic formula AH) is typically a water-soluble, sour-tasting chemical compound. ... Hydrogen cyanide is a chemical compound with chemical formula H-C≡N. A solution of hydrogen cyanide in water is called hydrocyanic acid or prussic acid. ... For a list of biologically injurious substances, including toxins and other materials, as well as their effects, see poison. ...

Because of the above mentioned there is a controversy among pseudo-scientists trying to disprove the holocaust. It is a common argument that because the levels of cyanide (Prussian blue) are higher on the walls of the delousing chambers than the homicide chambers, the homicide chambers were not used to any extent. Anyone that understands the properties of iron bonded cyanide and cyanide gas can easily refute this. A controversy is a contentious dispute, a disagreement over which parties are actively arguing. ... Concentration camp inmates during the Holocaust The Holocaust was Nazi Germanys systematic genocide (ethnic cleansing) of various ethnic, religious, national, and secular groups during World War II. Early elements include the Kristallnacht pogrom and the T-4 Euthanasia Program established by Hitler that killed some 200,000 people. ...

"Prussian Blue" is also the name of both a white power band consisting of twin preteen girls, and an English rock band that actually holds the copyright to the name. White Power is a phrase thought to have been coined by George Lincoln Rockwell during a white supremacist rally in Marquedt Park, Illinois in 1967 (whereby the term began being uttered sponteniously). ... For copyright issues in relation to Wikipedia itself, see Wikipedia:copyrights. ...

See also

• potassium ferrocyanide
• potassium ferricyanide

Potassium ferrocyanide (K4Fe(CN)6·3H2O), also known as yellow prussiate of potash, is a coordination compound forming lemon-yellow monoclinic crystals at room temperature and decomposing at its boiling point. ... Potassium ferricyanide (K3Fe(CN)6), molecular weight:329. ...

External links

• http://www.nlm.nih.gov/medlineplus/druginfo/uspdi/202737.html (note: this is not in the public domain, even though it is on a .gov site)
• The FDA's page on prussian blue: http://www.fda.gov/cder/drug/infopage/prussian_blue/Q&A.htm