Lichtenberg figures may also appear on the skin of lightning strike victims. These are reddish, fernlike patterns that may persist for hours or days. They are also a useful indicator for medical examiners when determining the cause of death. Lichtenberg figures appearing on people are sometimes called lightning flowers, and they are thought to be caused by the rupture of small capillaries under the skin due to the passage of the lightning current or the shock wave from the lightning discharge as it flashes over the skin. A lightning strike can also create a large Lichtenberg Figure in grass surrounding the point struck. These are sometimes found on golf courses or in grassy meadows. Fulgurites may also be created as sand and soil is fused into glassy tubes by the intense heat of the current.