Raw opium may be sold to a merchant or broker on the black market, but it usually does not travel far from the field before it is refined into morphine base, because pungent, jelly-like raw opium is bulkier and harder to smuggle. Crude laboratories in the field are capable of refining opium into morphine base by a simple acid-base extraction. A sticky, brown paste, morphine base is pressed into bricks and sun-dried, and can either be smoked, prepared into other forms or processed into heroin.