[mass noun] A form of diatomaceous earth used in various manufacturing and laboratory processes, chiefly as a filter, filler, or insulator.
- ‘Fiberized asbestos or ‘magnesia’ is a component of many insulating compositions which may also contain clay, kieselguhr, fossil meal, flax, hemp or jute waste and other materials.’
- ‘Conventional beer filters are made of either densely packed fibres or a dusty material called kieselguhr, which consists of fossilised hard-walled algae called diatoms.’
Late 19th century: from German, from Kiesel gravel + dialect Guhr (literally yeast) used to denote a loose earthy deposit, found in the cavities of rocks.
We take a look at several popular, though confusing, punctuation marks.