How to Lighten the Color of Stone

Oven Heating

• 1

  Place the stone on a baking sheet in the oven. Stones will begin to change color at 315 degrees Fahrenheit. Heat the stone, starting at a low temperature, and check it every hour to see if the color has changed.

• 2

  Increase the temperature by 100 degrees every hour. Stones can tolerate up to 3,500 degrees Fahrenheit, so don't be afraid to turn the oven as high as it will go.

• 3

  Cool the stone slowly with the oven off and the door closed to prevent cracking.

Blowtorch Heating

• 4

  Wear heavy work gloves to protect your hands from getting burned. Turn the blowtorch on to a medium setting.

• 5

  Pick up the stone with metal tongs and hold it in the flame for three minutes. If you see the stone start to crack or warp, it has gotten too hot.

• 6

  Remove the stone from the flame and check the color. Heat it for a minute more at a time to achieve the desired color.

Sunlight Bleaching

• 7

  Place the stones on a reflective surface like a baking sheet. This will attract the sunlight and help intensify the heat.

• 8

  Lay the baking sheet out in a sunny spot.

• 9

  Check the stone daily for lightening. The sun can take weeks or even months to lighten a stone.