This is a magnificent large brooch that is a real statement piece because of the pristine quality of the stone, the enormous size, and the simple understated design. This piece was done by Eunice Ruddy who signed her work with an “E” inside a mushroom shape. This piece is so-marked along with the stamp of “Sterling” on the back. She called her works, “Euniques” and trademarked them in 1977, but only lived until 1984, so I’m not sure how much of her work is out there. This brooch is incredibly well-crafted and an absolutely superb work by way of its” less-is-more” design and the most beautiful piece of malachite I have ever seen. It is a very large cabochon, bezel-set inside a flat rim that is an extension of the back. It measures 1-1/2” diameter X ½” high. The stone itself shows ¼” above the bezel. It weighs a substantial 34.8 grams. It is in perfect vintage condition with no damage on the silver or the stone and the roll clasp works perfectly. This piece dates sometime prior to 1980 and is a fabulous work of art.