A fab retro 1970s pendant and chain from the Adeline range by Ralph Weston. The pendant is a concave circular shape with an inner smaller round disc mounted with a central flat reddy green abalone shell. It is Modernist and minimalist in style. Stainless steel metal with a satin finish, stamped with the designer's logo to the reverse. Silver steel colour.
Stainless steel pendant is 44mm diameter. Steel chain is typically 70s with large links and no opening forming a 26" slip-on necklace - so quite long.  The pendant sits at about heart height. It's not heavy or too chunky. I think this Ralph Weston is the same Ralph Weston who still makes jewellery today from the Peak District.
Very good condition, vintage 1970s (or so), very wearable... 
Comes in presentation box. Free P&P to the UK.