Solid 10K Gold Pendant With Natural Blue Sapphire And Natural Diamond

Very pretty vintage open heart pendant with the Earth mined blue Sapphire and the Earth mined colorless diamond. Real solid 10 karat gold. Stamped 10 K and has a makers mark. I don't know enough to say whether the sapphire, although Earth mined, has been enhanced in any way. But it has some visible inclusions and it's size is not too large, so it may well be not heated or treated in any other way. Also, it changes color from very dark blue in shade to very sparkly blue in direct sunlight, which is what natural sapphires do.