Amphetamine
In the United Kingdom, the most common type of amphetamine is powdered amphetamine sulphate, although diverted pharmaceutical supplies of  Dextroamphetamine or Methylphenidate (Ritalin) are also seen.
Powdered amphetamine is usually an off white colour and usually illegally produced in laboratories. Sometimes 'coloured' amphetamine is seen, commonly referred to as 'pink champagne' though their is little evidence that this is anything other than normal amphetamine mixed with food colouring.
In other areas of the world, diverted pharmaceutical supplies are more common. In some areas of the Near and Middle-East (particularly Saudi Arabia) counterfeit amphetamine tablets are becoming increasingly common, often branded as Captagon.