I'm not sure if these are succulents or even plants for that matter, but if you can identify them then I'd love to have one!
Hi Natalie, these are a plant - odd though that may seem.
I have grown Lithops which goes by the common name of Living Stones, but there are also other 'Pebble Plants' that are similar in that they grow like a little stone, to protect them from thirsty animals.
Some of the other similar genera are Ophtalmus, and Conophytum. There are so many different species, and they're all fascinating and gorgeous.
Be warned; these are even more addictive than other types of succulents; you can grow so many more in a small space, like a window sill.
Sorry I don't know all that much about them, but they do have specific requirements for dormancy, and they're easy to kill with kindness. Be aware of their needs before you get too carried away and buy a whole bunch.
Hope that helps,
See how to grow Lithops here.