A living toad was liberated from a cavity near the center of a large rock by workman digging for ore at Paswick,Derby,England,
in 1852. They came upon the rock- actually a large lump of ore-at a depth of 12 feet,below ground level and since it was too
large for two men to lift,they began to break it up with their picks.
The cavity in which they found the toad was nearly 6 inches in diameter,considerably larger than the animal itself,and was
lined with crystals,perhaps of carbonate of lime.The toad dies very soon after exposure to air.
(Source, 'The Zoologist',10:3632,1852)