Richter Company, Germany, circa 1915.
(cardboard box 8.8" x 8.8" x 5/8", 52 colored stone pieces, 6.75" x 6.75",
with 12 page blue problem and green solution booklets of 36 patterns)

More of a two-dimensional building set than a puzzle. Described on page 86 of the Anchor Puzzle Book, this is one of a number of Richter "Mosiac" puzzles made in the World War I time period that used colored tiles. The tiles are colored differently on each side; below is shown the arrangement shown above flipped over (in the horizontal direction), and two sample pages from the problem and solution booklets: