Niels Østergaard Knudsen silver Brutalist ring with moonstone or a quartz stone - Size 54

Niels Østergaard Knudsen, Brutalist ring with moonstone or a quartz stone. This is unmarked but Niels Østergaard Knudsen was a goldsmith in Charlottenlund from 1964 to 2008. Ring size 54. Excellent condition.