- A very soft, soapy-feeling mineral that is a silicate of magnesium, sometimes with small amounts of aluminum silicate. Talc is used in making dusting powder (talcum powder), in cosmetic preparations, and as a filter aid in pharmacy. The inhalation of talc can lead to a chronic lung disease called talcosis which is related to silicosis. It occurs in workers exposed to talc mixed with silicates. Talcum powder often used to contain traces of asbestos (because talc and asbestos form under similar circumstances and are commonly found together in the earth). Since asbestos can cause cancer, it is now removed from talcum powder.
* * *Native hydrous magnesium silicate, sometimes containing small proportions of aluminum silicate, purified by boiling powdered t. with hydrochloric acid in water; used in pharmacy as a filter aid, as a dusting powder, and in cosmetic preparations. SYN: French chalk, soapstone, talcum. [Ar. talq]* * *talcum
* * *talc 'talk n a very soft mineral Mg3Si4O10(OH)2 that is a basic silicate of magnesium, has a soapy feel, and is used esp. in making talcum powder
* * *n.a soft white powder, consisting of magnesium silicate, used in dusting powders and skin applications. Talc used to dust surgical rubber gloves causes irritation of serous membranes, resulting in adhesions, if not washed off prior to an operation.
* * *(talk) a powdered hydrous form of magnesium silicate, sometimes containing a small proportion of aluminum silicate; solid lumps found in nature are called soapstone or steatite. Inhalation of the powder can cause talc pneumoconiosis. [USP] a purified form of talc used as a dusting powder and pharmaceutic aid. Called also purified t.
Medical dictionary. 2011.