I do not know what you mean by "property" but these are some things that can be used to distinguish both minerals from each other:
- Gypsum is a sulfate mineral, talc is a clay mineral.
- Gypsum is one degree harder than talc.
- Gypsum is soluble in water, talc is not.
Hope it helped,
BioTeacher101
(If you have any questions feel free to ask them in the comments)