crocoite การใช้

• In 1797, Louis Nicolas Vauquelin received samples of crocoite ore.
• A bright yellow pigment made from crocoite also became popular.
• Cross-joints show beautiful pyromorphite and crocoite, occasionally also cerussite.
• Only some joints are covered in pyromorphite and crocoite.
• He produced chromium trioxide ( CrO 3 ) by mixing crocoite with hydrochloric acid.
• Crocoite is also the official Tasmanian mineral emblem.
• The crocoite appears skeletal and the pyromorphite acicular.
• It occurs naturally as the mineral crocoite but the mineral itself was never used as a pigment in paintings.
• To the north follows a 10 centimeter wide band of white, powdery mylonite very rich in pyromorphite and crocoite.
• As crocoite is composed of lead ( II ) chromate, it is toxic, containing both lead and hexavalent chromium.
• The " Adelaide Mine " near Dundas was the location of special specimens of Crocoite and other rare minerals.
• Berezovsk Mines were for a long time the only source for crocoite and therefore the only source of the pigment chrome yellow.
• Next comes a 5 centimeter wide quartz band in boxwork facies, that is also very rich in the secondary minerals pyromorphite and crocoite.
• "' Crocoite "'is a mineral consisting of lead chromate, O 4, and crystallizing in the monoclinic crystal system.
• The discovery of crocoite by Johann Gottlob Lehmann in 1766 at the Berezovsk Mines was the starting point of the discovery of the element chromium.
• At first, crocoite from Russia was the main source, but in 1827, a larger chromite deposit was discovered near Baltimore, United States.
• It may be associated with cerussite, plattnerite, azurite, malachite, pyromorphite, mimetite, beudantite, duftite, crocoite, gibbsite, allophane and limonite.
• In 1797 a French scientist Louis Vauquelin discovered the mineral crocoite, or lead chromate, which led in 1809 to the invention of the synthetic pigment chrome orange.
• Oxidation of Cr 3 + into CrO 4 2 " ( from chromite ) and decomposition of galena ( or other primary lead minerals ) are required for crocoite formation.
• Though misidentified as a lead compound with selenium and iron components, the mineral was in fact crocoite ( " lead chromate " ) with a formula of PbCrO 4.