Buff decided to move along some of her collection of interesting art objects, including 5 Mexican gods of unknown name and origin. I'm going to dig a bit--Buff thought they were possibly Mayan but I am not sure; they could be Aztec or Nahua inspired, though they were carved sometime in the mid 20th century, 1960-1980. I found out that some were sold as tourist items in a shop in Reynosa, Tamaulipas state, Mexico. (this via the helpful robertl4072, Robert Lochhead, who has an ebay store and more of these guys for sale, plus other neat items.) The stone is very heavy and dense, with reflective inclusions and very smooth and polished. Each god fits nicely in the palm of one's hand. I need to make a little case for them with something to keep them upright and in place, as they tend to want to topple over on their own.
OK a bit of googling makes me think they are made of rainbow obsidian, which would explain why it feels like heavy glass. Later Robert looked at the photo here and said yep, those were from his grandfather's shop.