I have a ?white gold solitaire ring with 3.00 14K stamped inside band on one side and ULTRAGEM <SD> stamped on other. What does this mean?

14K means 14 carat gold, ultragem made synthetic gems (I guess SD stands for synthetic diamond). The 3.0 may be the carat weight of the synthetic diamond.

I have a 14kt white gold ring that says ultragem but no sd mark, could it be [email protected]