I believe one to be cultured, and the other one to be.... not. LOL. The more yellow gold clasp has a 14K on it and it belongs to a 20" strand of ~6.5mm pearls. It feels glassy, heavy. This ex said he bought them at Bailey, Banks and Biddle. The other strand, more of a dark gold, or brass, has no markings. They are a bit brighter (whiter) than the other. And of course the clasp won't unjam right now, so I can't measure them, but they seem to be about 23" with maybe 7.5mm. Also knotted, but they just feel cheaper. Appreciate your help!