Perfection. I purchased this at Brimfield from a seller as obsessed with matte green Arts and Crafts era glazes as I am--and we agreed on this as about the most perfect, super rich green we had--have--seen. Plus this gorgeous faceted form, beautiful and a very satisfying thing to hold. Of a large tumbler scale, it could be used for a big cup of coffee, but I'd be inclined to use it as a vase, perfect for red berries on a holiday table or for a bunch of daffodils in the spring--or anything. 

4 5/8" t x 3 3/4" in diameter and in very good condition, earlyish 20th c. The yellow bottom suggests Zaneware/Zanesville but no mark and I'm not entirely sure. Photos do no justice (I find this green very hard to photograph), just gorgeous.