Definition of secede - withdraw formally from membership of a federal union, an alliance, or a political or religious organization Definition of secede - withdraw formally from membership of a federal union, an alliance, or a political or religious organization
A shell casing is a piece of ammunition that is made of metal. It is often brass, but it can be made of other metals as well, and the more durable the better. Shell casings can be made from any kind of ammunition that is fired from a pistol, rifle or shotgun. It is not a bullet, but it is a piece of the larger ammunition mechanism that is loaded into the chamber to be shot.
Similarly, what about coquina...a rock made entirely of seashells? Shells are made of mineral matter, but they aren't minerals any more than teeth are. Finally, we have the exception of obsidian. Obsidian is a rock glass, in which little or none of its material has gathered into crystals. It is an undifferentiated mass of geological material, rather like slag but not as colorful.