After a winter long ring drought I'm happy to be back in the game with a ring. Only silver but I welcome it to my collection. Not sure of the stone.
Yes it is actually only half of a dime. I suspect it is silver but there is no date... sorry if you feel tricked.
Its probably black Onyx although in some of the Mexican jewelry I have seen black glass substituted for onyx. Half a silver dime is better then a nickle!!!