This is a retro style, silver tone necklace by J by Jasper Conran.  It is made from silver tone flat snake chain with a central feature of abstract shaped blue and sparkle shapes linked together. 

It has a lobster claw clasp. 

It is secondhand in good condition with some minor wear/tarnish.

The necklace is approximately 48 cm in length with an extender, or 43 cm without the extender.