Provenance is 50% of the piece. Stone objects are extremely hard to authenticate. The fakes are amazing.
Without provenance you have nothing. Especially with stone. Coulda been made 2,000 years ago, coulda been made 20 years ago. Stone is the hardest medium to date.
Good provenance can be the difference between a $200 piece and a $200,000 piece i.e. there's a published archaeological report with sketches of the piece when it was excavated in Mexico in 1930.
If you didn't spend a ton of money on them just have fun tracking down some experts and work on authenticating them. Buy a 10x loupe and examine them for tool marks. Some guys own those USB microscopes that plug into your computer.
Look up some antique dealers in your area or artifact galleries, Mexican art galleries etc. and I'm sure you'll find some old-timer somewhere that can take a look at them for you.
The objects in your very first picture might be Costa Rican but I don't know for sure. I've heard them described as 'death effigies' or things that were carved in the likeness of someone who passed away and kept as a memento. Maybe Mayan(?), I can't remember which culture. I mostly know Olmec. The figure on the far right doesn't look correct. Looks like tourist giftshop stuff. One spoiled apple can ruin the bunch so if one piece in a collection doesn't smell right, look hard at the rest.
The celts in your other pictures look good tho. Ceramics I don't keep up on.
