The band is flat and plain, tapering slightly inward at the shoulders. The top is a large gallery with four angled prongs set in a square when seen from above. These grasping an open collar set with a brilliant-cut blue crystal, possibly crystal, aquamarine or topaz. The stone and ring are in excellent condition.
The silver has a very slight hint of yellowish and there is heavy tarnish inside the setting, but I prefer not to clean vintage pieces, leaving that decision to the new owner.
The band is marked inside, 835 and an unidentified logo of a bird in flight, or possibly a mushroom, depending which way you look at it. There are tiny Swedish import marks on the outside of the band. I would guess it comes from one of the other Nordic countries, or possibly Germany.
The ring size is small, about 5.5 US, K UK. It can be re-sized. The stone measures just over 3/8 inch in diameter and with its setting sits 5/8 inch above the finger.