Beautiful Black Umbonium. Though in reality they are more of a grey than black. Tried showing true color with pictures. Both with and without the flash. They are natural so could be used in an aquarium. Size does vary but none are more than 1/2 inch across so they are small. Perfect for mirrors, wreaths, wind chimes, picture frames, shell flowers, shell layer sculpture figures! This shell is limited only by your imagination. They are natural and have slight differences in stripes and spots from one to the next ! I have tried to show that with the picture. Price is per approx 4 oz. Stop in and visit our e-store for many more great choices. Will gladly give shipping discounts and or ship internationally.---------If you add us to your favorites list you will be updated by e-bay when we list new items. Don't forget to sign up for our monthly news letter !