This Yellow Fiber Optic glass block measures 4.75 inches x 4.62 inches x 1.3 inches and weighs 2.5 pounds.

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 character 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.