Semi precious cabochon stones with flatback. Measuring 18x13mm, these are Aventurine. Aventurine ranges from a dusty blue-green to a lighter, washed out blue-green and sometimes a yummy light medium green. It looks beautiful with silver and silver plated findings. So reasonably priced, too....with semi precious stones there is substance and you can really build value into your work by using them. Aventurine is a very popular stone as well. We cull our stones for quality to make sure of no cracks or chips and that the over-all appearance of the stone is very pleasing. You should expect variations in all natural, semi precious stones. Looks great in any of our mounts and I love it in the new pewter findings from B'sue by 1928. No two are exactly alike. Sold by the piece.