PETERBOROUGH, N.H. — On July 30, a diamond cocktail ring set in platinum brought $10,800 at the first sale conducted by Peterborough Auctions. Featuring a 2.15-carat European-cut diamond, surrounded by an additional 2.24 carats of accent diamonds, the ring was the top lot in the sale, and it was one of numerous other pieces of jewelry in the sale. Mid-Twentieth Century silver included a Gianmaria Buccellati Empire-Impero sterling silver flatware service for 12, with additional pieces, which earned $4,500. Other silver included Mexican examples and pieces by Tiffany. Probably going back to Puerto Rico, a 1950 city scene, “Utuado, Puerto Rico,” by artist and political dissident George Warrek, earned $3,000. Prices quoted include the buyer’s premium as reported by the auction house. The sale included almost 300 lots and a full report will follow.