Check the listing for details. Clear Cracked Glass Cabinet Knob by Gemstone Hardware. Color: Clear, Condition: New. Listed at 10.00 USD. This Clear Cracked Glass is eye beautiful sitting next to a crystal quartz sphere. These pictures do not do it justest. Retail at $16 our sale price is $9. Crystalline Cracked Glass has no color it's clear with many cracks to reflect light. Gemstone Hardware is the only business who offers this Cracked Glass Knob. The 1 1/2" spheres are created using high heat followed by rapid cooling that results in intricate patterns of cracks & fractures that capture light then heat to make it solid, making each piece a one-of-a-kind work of art. A beautiful addition to our line of products adding a different twist on the beauty of gemstones at a lower price. Each knob comes with a 1" screw. Choose from 5 of our Patent hardware finishes. We have 7 colors.