This lovely antique, art nouveau (est. 1915) 4 leaf clover pendant measures approximately 35mm x 30mm. The necklace as a whole is approximately 53cm (21 inches) in length. The necklace is a beautiful, warm, and very lustrous 18k gold with a .10 est. round cut H/SI1 sparkling diamond. Beautiful patina commensurate with age. 

Hallmarked for 18k.
Gemoro tested. 
Weight is 8.39 grams.