The term black stone has several synonyms that can be used in different contexts. For instance, obsidian is a volcanic black stone known for its sharp edges and shiny appearance. Onyx is another black stone that is often used in jewelry and decor. Jet is a black stone formed from fossilized wood and is commonly used for carving and ornaments. Schorl, also known as black tourmaline, is a protective stone often used in metaphysical practices. Finally, basalt is a black volcanic stone commonly used in construction due to its durability and strength. All of these stones have distinct qualities and uses, making them fitting synonyms for the term black stone.