Natural turquoise heart pendant on fine sterling chain

Simple, lovely, just over an inch in each direction. The bail is the hook the top of the metal piece that goes through a small top to bottom hole in the turquoise. The 17-inch chain is marked on the clasp: 925 (in two places), MEX and initials I think are JS. The piece weights 8g. In very good shape, with natural brown veins through the turquoise and minor scratches on one side.