Sterling.
sterlized
plated sterling silver
In newer designs Ive seen where Ster/10K indicates that the ring is sterling silver, plated with 10K gold. In older designs, the 2 stamps usually mean that part of the ring is sterling and part of the ring is 10K gold.
I Believe It would be the ring being sterling silver with 10k black hills gold.
STER is short for STERLING, which is 92.5 silver.
Ster Century was created in 1996.
Ster cinemas was created in 2004.
Ster van Zwolle was created in 1961.
Ster ZLM Toer was created in 1987.
stamp tiffany and co ster 926. other side states Rockefeller university 1901
Ster means fine. Stereo means solid.