Celtic Cross Necklace Sterling Silver Connemara Marble & Marcasite Irish Made Celtic Cross necklace measures approximately 1 1/4" tall x 3/4" wide and comes on an 18" silver standard chain. Crafted from sterling silver and marcasite, featuring Connemara marble in the center. Nickel and allergy free! Connemara marble is naturally occurring, so each piece is a unique color. ler Made by Solvar Ltd. and hallmark stamped in Dublin, Ireland.l