Dunnite

Dunnite, also known as Explosive D or ammonium picrate, is an explosive developed by Major Dunn in 1906. Ammonium picrate is a salt formed by reacting picric acid

Picric acid

Picric acid is the chemical compound formally called 2,4,6-trinitrophenol . This, a yellow crystalline solid, is one of the most acidic phenols. Like other highly nitrated compounds such as TNT, picric acid is an explosive...

 and ammonia

Ammonia

Ammonia is a compound of nitrogen and hydrogen with the formula NH₃. It is normally encountered as a gas with a characteristic pungent odor. Ammonia contributes significantly to the nutritional needs of terrestrial organisms by serving as a precursor to foodstuffs and fertilizers...

.
It was used extensively by the United States Navy

United States Navy

The United States Navy is the sea branch of the U.S. Armed Forces. It is one of the seven uniformed services of the United States. As of 31 December 2008, the U.S. Navy had about 331,682 personnel on active duty and 124,000 in the Navy Reserve. It operates 283 ships in active service and more than...

 during World War I

World War I

World War I , also known as the First World War, the Great War, and the War to End All Wars, was a global military conflict which involved most of the world's great powers, assembled in two opposing alliances: the Triple Entente and the Triple Alliance...

.

Though Dunnite was generally considered an insensitive substance, by 1911 the United States Army

United States Army

The United States Army is the branch of the United States Military responsible for land-based military operations. It is the largest and oldest established branch of the U.S. military and is one of seven uniformed services...

 had abandoned its use in favor of other alternatives. The Navy

United States Navy

The United States Navy is the sea branch of the U.S. Armed Forces. It is one of the seven uniformed services of the United States. As of 31 December 2008, the U.S. Navy had about 331,682 personnel on active duty and 124,000 in the Navy Reserve. It operates 283 ships in active service and more than...

, however, used it in armor-piercing artillery shells

Armor-piercing shot and shell

An armor-piercing shell is a type of ammunition designed to penetrate armor. From the 1860s to 1950s, a major application of armor-piercing projectiles was to defeat the thick armor carried on many warships. From the 1920s onwards, armor-piercing weapons were required for anti-tank missions.An...

 and projectiles, and in coastal defense.

Dunnite typically did not detonate on striking heavy armor. Rather, the shell encasing it would penetrate the armor, after which the charge would be triggered by a fuse .

In 2008 caches of discarded Dunnite in remote locations were mistaken for rusty rocks at Cape Porcupine, Newfoundland and Labrador

Newfoundland and Labrador

Newfoundland and Labrador is a province of Canada on the country's Atlantic coast in northeastern North America. This easternmost Canadian province comprises two main parts: the island of Newfoundland off the country's eastern coast, and Labrador on the mainland to the northwest of the island.A...

, Canada.