Shellite (explosive)

It was typically used as a filling in Royal Navy armour-piercing shells during the early part of the 20th century.

Shellite originated after World War I as a development of lyddite (picric acid).

During the war, lyddite-filled, armour-piercing shells had been found to be shock-sensitive, with a tendency to prematurely detonate upon impact rather than after penetrating the target's armour plate.

[3] The first trials of shellite took place in 1921, when the British monitor HMS Terror experimentally fired different types of 15 inch (381 mm) shell at 500-yard (460 m), point-blank range against the surrendered German battleship SMS Baden.

These crystals are extremely shock sensitive and it is recommended that wrecks that contain shellite munitions not be disturbed in any way.