Vintage Agate heart necklace brass chain

This is a very pretty and vintage necklace that has a brass chain with a polished heart-shaped agate for the pendant. The pendant is 2 in long and 1 1/2 in wide and the chain is 25 in. Overall good condition. There is some very pretty variation in the stone especially when you look at it through the light. great piece for layering with other long necklaces also. I believe it is a 1960s pendant but cannot be sure.