This block of White Fiber optic glass measures 4 3/4 inches by 4 5/8 inches by 1 1/8 inches and weighs 2.5 pounds

Photos were taken under sunlight while wet

Fiber optic glass is a man-made glass composed of millions of glass fibers that have been fused together into a block. This creates a reflective characteristic known as cats-eye. This material can be slabbed easily with a diamond blade. It is a great material for making cabochons as well as flint knapping into arrowheads, spears or other shapes.