Starfish and Blue Oval Pendant Set

Silver starfish appears to be set with opal chips. Well made, cannot find a silver hallmark- only a maker mark - Cardenas. please view front and back as pictures indicate. Including the bail about 1.5 inches high and 1 inch wide. Blue cats eye likely a synthetic stone- but nice color and no chips. The back is stamped Alpaca - not genuine silver. About an inch and a quarter high from bail. Neither genuine sterling- priced to reflect this.