Simple Modernist 1960s cabachon pewter chunky ring.  Handmade by H+F, Denmark, and fully stamped on the reverse with ‘H+F Handmade in Denmark’ in a round logo.
 
Bracelet shown in photos available here.
Slightly adjustable, currently a size 6.5-7.
Stunning round, pale purple stone
Simple, round mounting
The pewter is a grey metal with only a slight shine. 
Middle stone metal surround is a statement 7/8” wide
Band is 1/2” wide at its widest.