These rather special  Goldstone blue tumbled stones

are Medium size

Goldstone blue this is dark blue with tiny copper glitter. Goldstone is a man-made stone, just a type of glass with glittery metallic material in it. It is a valid classification, as it has many properties of NATURAL glasses, such as obsidian, which are modified by its being man-made and having been doped with additives. Originally created when alchemists were working towards creating gold. Gently uplifting, mildly helpful to reduce stomach tension and protect the centre of the body.