The main serpentine group minerals are antigorite, chrysotile, and lizardite. The main thing you need to know in order to distinguish between them is that chrysotile is fibrous, and antigorite and lizardite are not. Easy.
You should probably also know that chrysotile is both asbestiform and a form of asbestos. Touching it won’t hurt you, but snorting, licking, or otherwise ingesting it is maybe not so smart.
Sheets of linked tetrahedra
Fibrous/asbestiform (chrysotile only)
|Hardness||3 to 5|
|Specific gravity||2.5 to 2.6|
|Cleavage||Perfect (001) (antigorite)
Anomalous interference colors:
blues, greys, greens, yellows
|after Perkins, 317-318|