This is a secondhand necklace by Marks and Spencer.  The necklace is made from chain with blue stones and a flower.  It has a central Y-drop. 

It has a lobster clasp.

It is secondhand in good condition with some minor signs of wear/tarnishing.  

The necklace is approximately 38 cm in circumference, excluding the clasp.

The Y-drop is approximately 2 cm in length