These are 10 mm round rhodonite cabochons.
Rhodonite is a natural stone that is a pretty medium pink in color with dark dendritic inclusions that form an interesting pattern.
As with all natural cabochons, no two cabochons will be exactly alike.
Rhodonite measures a 5.5 to 6 on the Moh's scale of hardness.
Sold as a package of 6 cabochons.