No, salt is generally not considered a gem.
While the mineral halite, which is the chemical compound sodium chloride (NaCl) and what we commonly know as salt, is a mineral, it's rarely used as a gemstone. This is due to several factors:
- Solubility: Salt is highly soluble in water, making it difficult to work with and easily damaged. A gem must be durable, and salt is not.
- Softness: Halite is very soft (2.5 on the Mohs hardness scale). Gems should be hard so they don't scratch easily.
- Rarity of Facetable Material: Although halite is common as a mineral, clear, flawless crystals large enough to facet into gems are rare. While it can be faceted, it's unusual.
Although, due to the above, Halite is not regarded as a gem and is more commonly known as rock salt. It is used in industry and sometimes available to be purchased as a mineral sample.
