Review on Dazzling JINGLING Diamond Coated Lapidary Jewelry: Sparkle with Elegance and Style! by David Bowens

I do faceting as a hobby and find these 1.8mm diamond drill bits suitable for Drilling into softer stones like turquoise, malachite, rhodochrosite and obsidian (natural glass). They make a small hole with a diameter of approx. 2 mm and are designed for speeds of up to 18,000 rpm. They have a double-edged point (see figs 2 and 3) which helps to supply lubricating water to the hole being drilled. Please note that these are NOT "carved burrs" but simple thin wire drill bits. All diamond grit drills MUST be used with water to lubricate the drill. This removes the grinding and reduces tool wear. I've found that using non-hardening Plumber's Putty to create a dam around a drillable rock surface works well when I can't direct a steady stream of water at the rock or drill into a shallow container underwater. ALSO, you NEED to know that this slowly "grinds" the glass or stone/gemstone, not "cuts" through wood or metal like a jagged burr. With this tool, diamond grit is applied outwards in a thin layer; much more expensive versions use a thicker layer of sintered diamond. Excessive pressure will damage and render your diamond drill bit unusable - slow and intermittent light up and down pressure will allow water to enter the hole and carry away the cutting debris. Remember to protect your hands and eyes as broken glass and stones can seriously injure you. I drill extra slowly when approaching the breakout point to avoid chipping the stone; Sometimes I can flip the part to be drilled and work from the back to hit the hole I started if I can line it up correctly. They are not designed for holes deeper than say 1cm unless you are willing to use multiple bits as the tip usually wears out first. Diamond shank drill (another more expensive brand). When I use them on a hard gem they don't last very long (jade, agate, ruby zoisite etc.). I recommend this JINGLING Brand 1.8mm Lapidary Diamond Burs Stone Carving Burs Pack of 10. Please note the listing says 20 pieces but ONLY 10! Because of this and also because of the overall performance, 4 stars are justified. I hope you found the information and my review helpful.