talc

noun

1. (countable, obsolete, uncountable)Originally a large range of transparent or glistening foliated minerals. Examples include mica, selenite and the hydrated magnesium silicate that the term talc generally has referred to in modern times (see below). Also an item made of such a mineral and depending for its function on the special nature of the mineral (see next). Medieval writers adopted the term from the Arabic.
2. (countable, obsolete, uncountable)A microscope slide made of a plate of mica, generally in use from the start of modern microscopy until the early nineteenth century, after which glass slides became the standard medium.

   “M. [Antonie van] Leeuwenhoek fixed his objects, if they were ſolid, to the foregoing point with glue; if they were fluid, he fitted them on a little plate of talc, or exceeding thin blown glaſs, which he afterwards glued to the needle, in the ſame manner as his other objects.”

3. (countable, uncountable)A soft mineral, composed of hydrated magnesium silicate, that has a soapy feel and a greenish, whitish, or grayish color, and usually occurs in foliated masses.

   “The abeer is often mixed with powdered talc to make it glitter, and then, if it gets into the eyes, it causes a good deal of pain.”

   “With this background and experience we feel justified in stating that not all talcs contain, or are associated with, asbestos.”

   “For example, Montana talcs approximate the theoretical composition, while California talcs often contain calcite (CaCO₃) and dolomite (CaCO₃ • MgCO₃).”

   “Micronized talcs and, to an even higher degree, submicrometer talcs significantly influence the processing parameters.”

4. (countable, uncountable)Talcum powder.

verb

1. (transitive)To apply talc to.

   “"Generous talcing" is applied not only to the naked bale, but to the inside of the wrapper, and after stenciling, to the interior of the package. This talcing is repeated, "if necessary, dependent upon the number of handlings up to and into stores for steamer loading."”

   “Three manufacturers have now produced separate designs for talcing boxes; one uses conventional techniques of brushing and vibrators, one is a fluidised bed and the third is an electrostatic applicator.”

   “Then he talced his hands, slipped on a new pair of rubber gloves, went to the shapeless thing at the other end of the table, and began to work.”