Nodules of natural turquoise (not dyed) on wooden bookends. Turquoise occurs in a wide range of shades, from green to blue. I accidentally photographed one of the bookends upside down, the one on the left in the first photo and on the right in the second photo. My apologies but you can still see the specimen.
Each bookend is approximately 3/8 inch (0.95 cm) wide, 3/8 inch (0.95 cm) deep, and 3/8 inch (0.95 cm) tall.