A bowl and a rock!
A pestle is the part of the mortar and pestle combo that you hold in your hand and looks like a club. It is used to grind cooking materials into powder.
Chemicals are ground into powder using a mortar and pestle.
Try Pestle as in Pestle and Mortar
The mortar is a bowl-shaped container used to hold the ingredients, while the pestle is a heavy tool used to crush and grind the ingredients in the mortar. The pestle is typically a heavy and blunt object, while the mortar is a bowl with a smooth interior.
http://www.phisick.com/images/apoth/mortar-and-pestle-brass-101.jpg
The word pestle is generally used in connection with the word mortar. It is from Latin pistillum, an instrument used for crushing; the mortar is a kind of bowl, and the pestle is used to crush a substance to powder in the mortar.
A mortar and pestle made of glass is typically used for grinding and crushing substances into fine powders or pastes. It is commonly used in laboratories for grinding chemicals or in kitchens for grinding spices and herbs. Glass mortar and pestle are preferred for their non-reactive nature and ease of cleaning.
for powdering...
a roman quern is just like a mortar and pestle, you just grind materials like wheat, flour, and grains, ect. p.s. a quern is a stone and a mortar and pestle is like a cup with a crushing stick. if you still don't get it then just look it up on google images to see how it looks bye now
A mortar and pestle are used to grind substances into smaller particles.
Pestle.
mortar and pestle