You can find information regarding propagating the seeds in our database:
Living Stones (Lithops)
I googled for images of Lithops seeds and found these photos for comparison:
In the line of photos beneath the first picture here, you can click on one showing seeds:
http://www.dhgate.com/product/...
https://www.flickr.com/photos/...
http://www.lithops.info/en/bot...
edited to add: I think you should plant them and watch to see what they turn out to be! I found this information on sowing Lithops seeds:
http://www.strangeplants.com/P...
I found these photos of Lithops seedlings:
https://blueskiez.wordpress.co...
And, photos of a Lithops seed capsule with and without seeds present:
http://www.lithops.info/en/bot...
