The beads listed in this store as "Yannin" were purchased at the Gem & Mineral Show in Tucson, Arizona, awhile ago and have been kept in my inventory. A search on-line did not bring up any similar items. The process used to make these used foil inside to reflect the light with an added special glass technique to create much depth of color.
This listing is for 7 10 x 12 to 10X13 mm rectangle cylinders. Corners are rounded with slight indentations on 4 sides to create a soft look.
Colors in photos above are fairly accurate and they are more of a satin finish than matte. Photos give some idea of the glow these beads have from within.