color of titanium oxide

This article discusses the discovery of phosphorescent lithopone on watercolor drawings by American artist John La Farge dated between 1890 and 1905 and the history of lithopone in the pigment industry in the late 19th and early 20th centuries. Despite having many desirable qualities for use in white watercolor or oil paints, the development of lithopone as an artists' pigment was hampered by its tendency to darken in sunlight. Its availability to, and adoption by, artists remain unclear, as colormen's trade catalogs were generally not explicit in describing white pigments as containing lithopone. Further, lithopone may be mistaken for lead white during visual examination and its short-lived phosphorescence can be easily missed by the uninformed observer. Phosphorescent lithopone has been documented on only one other work-to-date: a watercolor by Van Gogh. In addition to the history of lithopone's manufacture, the article details the mechanism for its phosphorescence and its identification aided by Raman spectroscopy and spectrofluorimetry.

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In conclusion, the wholesale classification of calcium carbonate is an important aspect of the calcium carbonate industry that helps categorize and differentiate the different grades of calcium carbonate based on their quality and intended use. Whether it is for pharmaceutical, food, industrial, or agricultural applications, there is a suitable grade of calcium carbonate available to meet the specific requirements of each industry. This classification system ensures that the right grade of calcium carbonate is used for the right application, ultimately leading to better quality products and improved performance.

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