Mortars and Pestles
Mortar and pestle implements have been used since ancient times to crush and grind substances into pastes or powders. Mortars can be made of hard substances like wood, metal, and ceramic, or from hard stone like granite or marble. Pestles are held in the hand, and usually have a tapered, club-like shape. A wet or dry substance is placed in the mortar, and the pestle is pressed and rotated against it until the material is pulverized.
The implements must be made of materials that are hard enough to crush the substance without wearing away, and they cannot be brittle or break from the pressure of manipulation. The material should also be cohesive to reduce chipping and non-porous to avoid absorbing or trapping the substances.
Some rough porcelain mortar and pestle sets can reduce substances to very fine powders, but are brittle and stain more easily. Porcelain mortars can be pre-conditioned by grinding sand that gives them a rougher surface. Glass mortars and pestles are stain resistant and suitable for liquids, but are fragile and do not grind as finely as ceramic sets. Metal mortars and pestles are popular for food preparation.
Mortars and pestles can be used in pharmacies to crush ingredients for a prescription, so they are commonly used as a symbol to indicate pharmacology. In pharmacies, the mortar may be made of porcelain and paired with a wood-handled pestle that features porcelain on the grinding end (head). This type originated in 1759 and is called a Wedgwood mortar and pestle.
Ingredients can be ground into each other to dilute, mask negative qualities, or add volume to facilitate handling through a process called trituration. Drugs can be finely ground when not available in liquid form, and supplements processed to be added for parenteral nutrition. Mortars and pestles are also used as drug paraphernalia.