I haven't seen one like this...a sterling silver polygon or 6 sided pendant with cz's inside and a faux emerald stone making a flower design in the center. On a sterling silver chain.  The chain can't be changed as it's 2 chains attached to the pendant. This is because it opens to a longer formal style necklace for your evening! This necklace can be 16 to 18" in length,  has an extender on the end. See the photos for the way it changes, with magnets.  No makers marks, only 925 stamped on this in 2 places.  Thanks for looking!