Vintage 925 Sterling Silver Modernist Brutalist Ring with Blue Sapphire (?)

Vintage sterling silver ring . Modernist Brutalist Mid-Century Modern. Wide hammered band. With an oval shaped light blue stone that looks like raw unfaceted blue sapphire (I think so, but can't guarantee it). The stone has some inner fairy glow and doesn't look like any other light blue stone that I know. Please see video and closeup pictures for details. Good quality. Handmade. In excellent condition. Measures as size 6-6.25, but due to its wide band, fits sizes 5.5-5.75 better (more comfortably). Not stamped, but was professionally tested as 925 sterling silver. Unisex, so will be listed in both men and women categories.