14.2.1 Background properties: 'background-color', 'background-image', 'background-repeat', 'background-attachment', 'background-position', and 'background'. This property sets the background color of an element, either a <color> value or the keyword 'transparent', to make the underlying colors shine through.
1 A spiral fracture happens when the break spirals around the bone, which can happen if the bone is twisted. 2  A compression fracture happens when vertebrae in the spinal column are pushed together in an accident or because of osteoporosis.
These crystals, often called shocked quartz, show a distinctive pattern of fracturing caused by high-energy impacts or explosions. Some scientists maintain that the fracture pattern in these quartz crystals could only have been caused by a massive asteroid or comet impact. The pattern is prevalent in quartz found at or near the Cretaceous/Tertiary (KT) boundary, the geological layer deposited at the time of the extinction.