A Diamond Burns - Borazon Remains Unaffected. Six-picture sequence shows how a small gem stone placed on a resistance heater disappears - burns up - when the temperature exceeds about 1600 degrees Fahrenheit. Borazon, General Electric's new man-made material which is in the same range of hardness as diamond, is not affected. These photographs were taken at 30-second intervals. (Note: Many materials withstand temperatures at which diamond burns; the significant part of this demonstration is that borazon combines the hardness of diamond with much greater resistance to oxidation at high temperatures. After the demonstration pictured here, the piece of borazon was used to scratch the face of another diamond.) (Second Note - to the ladies: Although diamond will burn, as shown here, relatively high temperatures are required. The oven in your kitchen range, for example, reaches only about 500 to 600 degrees Fahrenheit as compared with the 1600 degrees at which diamond begins to oxidize.)