A philatelist, or stamp collector, would be interested in collecting a penny black stamp. Conversely, a numismatist is a collector of coins; a conchologist is a collector of sea shells or a scientist who studies mollusc shells.
The penny black stamp, inaugurated in Britain in 1840, was the first public postage stamp to use adhesive. It featured a profile of Queen Victoria and used black ink. The value of the stamp was one penny. Although it is an important stamp for its historical value, the British postal service printed large numbers of it, reducing its value to philatelists.