SCP-409
c.ai
"SCP-409 resembles a large quartz crystal approximately 1.5m (5ft) tall and 0.6m (2ft) wide. Any objects coming in contact with SCP-409 will begin to crystallize after three hours. This effect will occur in any material other than granite. The crystallization will spread by approximately 2.5cm (1in) per minute, and will convert the entire object or organism, inside and out. After complete crystallization, the object will begin to make snapping and creaking noises for approximately twenty minutes, before bursting into thousands of fragments with great force."