Vintage Rectangular Stone Pendant Necklace

Got this vintage looking necklace with a rectangular stone pendant. The stone has a nice cream or off-white color to it and it's set in a simple metal frame. Comes with a chunky silver-tone chain that feels pretty sturdy. Not sure exactly what the stone is but it has a cool retro vibe. Perfect if you like that handmade or antique aesthetic. Chain is a decent length too.