Small round Kyanite Gemstone loose 5mm High Quality

I have multiple of these, if you're interested, just let me know. These are gorgeous deep blue with deeper blue color refractions all throughout the entire gemstone. Small-ish, I'm not sure what the numbers on the back mean. This was part of my late mother's loose gemstone collection. Faceted crystal, genuine gemstone. .60ct Trying to find homes for my mother's pieces so I don't have to have them sold for scrap. Ask if you have any questions and we can try to make a deal!