Your question is very general, and you don't say what sort of info you need (composition, occurence, diagnostic physical properties, etc), so it is only possible to give a general answer.
Those names are old terms for arbritrary divisions within the albite-anorthite feldspar series. They refer to feldspar with compositional ranges from 30-50% anorthite (=andesine), and 50-70% anorthite (=labradorite) respectively. They are still used in petrological descriptions, but they are not distinct mineral species.
Pete N.
Edited 1 time(s). Last edit at 02/14/2008 04:46PM by Peter Nancarrow.
