A group of coque de perle, mother of pearl and marcasite jewels, mid 18th century and later

A group of coque de perle, mother of pearl and marcasite jewels, mid 18th century and later, comprising: a coque de perle and marcasite pendant, length 7.9cm; together with three coque de perle and marcasite brooches, later brooch fittings; a mother of pearl and marcasite choker, length 26cm, hoop fittings intended for a ribbon; a pair of coque de perle and marcasite earrings, later mounted as earrings with gilt metal surmounts, length 5.2cm each, composite; a simulant pearl and cut steel necklace of fringe design, length 39cm; a marcasite necklace clasp; a section of coque de perle linking in gilt metal, length 14cm; a and a collection of similar jewel components variously set with mother of pearl, marcasite and coque de perle