Artisan Red Brown Stone 30" Necklace Metal Swirled Shell Accent 925 Clasp

Artisan Tumbled Red Brown Stone 30" Necklace Metal swirled shell accent appears to be handmade 925 clasp is hammered with a pictorial makers mark Mark is a capital S with a crown? Tumbled stone may be carnelian or fire agate. Some are banded stones. Most are solid colors. Not a lightweight necklace. Purchased new at an art show from the maker