Kaunis Koru Vintage Modernist 1960s Round Sterling authentic Silver Brooch Pin in Original Box

authentic Vintage, sterling silver, round, modernist pin/brooch made by Kaunis Koru Jewelry, a Finnish company founded in 1956. The company's mark is stamped on the back. This dates from the 1960s-70s. It is 916 sterling, as stamped on the back. It is 1 3/8" diameter, silver on the outside, and black coated silver in the concave center. It comes in its original box, and was purchased at Kaunis Koru Jewelry, Ghiardelli Square, San Francisco, CA.