Hashish, often known as 'hash', is a cannabis preparation composed of compressed and/or purified preparations of stalked resin glands, called trichomes, collected from the unfertilized buds of the cannabis plant. It contains the same active ingredientssuch as THC and other cannabinoidsbut in higher concentrations than unsifted buds or leaves. Hashish may be solid or resinous depending on the preparation; pressed hashish is usually solid, whereas water-purified hashishoften called 'bubble melt hash'is often a paste-like substance with varying hardness and pliability, its color most commonly light to dark brown but varying toward green, yellow, black or red. It is consumed by being heated in a pipe, hookah, bong, bubbler, vaporizer, hot knife, smoked in joints, mixed with cannabis buds or tobacco (the latter being more common in Europe and Africa), or cooked in foods. Hashish use as a medicine and recreational drug dates back to at least the 3rd millennium BC.
Contributions by SqueakBox, Fred J, and H.