Soda Fired Faceted Bottle Black/Blue Finish

Handmade bottles for sake, but also used as bud vases. Made partly on a wheel but with handbuilt elements. They are coated in a dark clay slip that contains cobalt, which reacts with the soda vapors in the kiln to produce a range of effects. Most of the surfaces are a dark metallic or stone-like black, some have a touch of blue poking through, some are more dramatically blue. I'll try to give a range unless otherwise specified. They were fired propped up on seashells, so the sides will have some marks and scaring from that, which is just inherent in the process. All are sanded though. About 5" tall.