This is a typical spectacular ring by the silversmith and jeweller, Michael A Bolton, probably made for a commission in the 1990s, using his 'caviar' technique with drops of molten silver.
 
Michael Bolton was the most remarkable self-taught silversmith and jeweller who we knew well until his sadly early death in 2005.  He was a larger than life character with a Father Christmas beard who made extraordinary pieces of jewellery, almost sculpture, and objet d’art and was ready to take on unique and often improbable commissions, some of which, mainly rings set with the most enormous gemstones from India, are in our possession.  He was a perfectly lovely man whose wife Margaret also made beautiful silver jewellery of a slightly less extravagant design.  Michael was also a natural teacher who taught a number of young jewellers their trade - he was passionate about silver and loved to let the molten metal form its own shapes.  Rings like this great chunk of silver were his earliest trademark pieces and are highly desirable and enjoyably wearable, not to mention pretty cool.  Michael made jewellery for several of the rockest rock stars who were on the impressive list of his patrons.
 
NB Do ask for more photographs of the ring on a hand - silver is difficult to photograph correctly under winter electric light!