The 93rd chemical mortar battalion was an army unit attached to U.S. infantry divisions during WWII. They were armed with 4.2 inch (107 mm) chemical mortars. Chemical mortars are so named because of their capability of firing not only high explosive, but also chemical, gas, incendiary and smoke marker shells. These mortars came to be acknowledged by U.S. army commanders and GI's as being one of the most effective means of quickly striking at stationary targets, such as machine gunnests, prepared strongpoints, pillboxes and even German artillery positions.
Black crackle with painted 93rd chemical mortar battalion insignia.