Blue chromates, basic

Chemical Properties. The valence states of chromium are +2, +3, and +6, the latter two being the most common. The +2 and +3 states are basic, whereas the +6 is acidic, forming ions of the type CrO (chromates) and (Cr203 [ (dichromates). The blue—white metal is refractory and very hard. 

Other Color Order Systems. The Natural Color System (24), abbreviated NCS, developed ia Sweden is an outgrowth of the Hesselgren Color Adas, and uses the opponent color approach. Here colors are described on the basis of their resemblances to the basic color pairs red-green and blue-yeUow, and the amounts of black and white present, all evaluated as percentages. Consider a color that has 10% whiteness, 50% blackness, 20% yellowness, and 20% redness note that the sum is 100%. The overall NCS designation of this color is 50, 40, Y50R iadicating ia sequence the blackness, the chromaticness (20 + 20), and the hue (50% on the way from yellow to red the sequence used is Y, R, G, B, Y). 

Copper chromates have been used as mordants in dying and in some pyrotechnic compns. For example a blue light rifle signal light compn developed at PicArsn(Ref 5) contained Cu(II) chromate 25, K perchlorate 65 Cu resinate 10% it burned at the rate 3.5in/min developing CP 485/sq in Refs l)Mellor 11(1931), 260 2)Ullmann 5 (1954), 588 3)Sax(l957), 5l6(Toxicity fire hazard of basic salt) 4)CondChemDict(l961), 30l(Prepn props of basic salt) 5)G.J. 

The highest aim would be to grasp that everything in the realm of fact is already theory. The blue of the sky reveals to us the basic law of chromatics. Let us not seek behind the phenomena - they themselves are the theory.37... 

Ferric oxide Pigment green 8 Ultramarine blue Wollastonite pigment, ceramic coatings Lead chromate pigment, ceramic glazes Cadmium Cadmium sulfide Lead carbonate basic... 

Perrit. A support, made of heat-resisting alloy, designed to carry vitreous enamel-ware through an enamelling furnace. Persian Blue. See Egyptian blue. Persian Red. Pigments of ferric oxide and basic lead chromate. 

According to Kiihn and Curran (1986), orange paste is an older term associated with basic lead chromate (lead chromate(VI) oxide, q.v.), as slated in their review of chrome orange and chrome red qq.v.) pigments. The term paste sometimes implies supply in the form of pigment thickly dispersed in some medium (for example as in paste blue and paste white lead, qq.v). 

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