If it's a species, aucampiae is as good a guess as any. But, lithops in cultivation can't really be identified, given hybridization, and variation within species. Flower color would be important to identification too, you'll have to wait a bit to find that out. Personally, I'd never claim to know what any of them are unless I trust the source, and it was labeled.
Anyways, unless you've been told it's a species, and it matches the description, it could be anything. There are a near-infinite amount of lithops hybrids, they all seem to hybridize with each other, and species are variable as well.
I think they need to seriously overhaul the taxonomy of Lithops at some point. There are too many species with small variations, known only from a couple locations.