Inorganic salts deposited in organic ground substance are known as mineral crystals or calcifications. These crystals are formed when minerals, such as calcium, magnesium, and phosphate, are deposited in the ground substance of organic tissues. The process of calcification is essential for the formation of bones and teeth, and it can also occur in other parts of the body, such as blood vessels and soft tissues.

The most common type of mineral crystal deposited in organic ground substance is hydroxyapatite, which is a calcium phosphate compound. Other types of mineral crystals that can be deposited include calcium carbonate, calcium oxalate, and magnesium phosphate. The composition of the mineral crystals depends on the pH and ion concentrations of the surrounding environment.

The deposition of mineral crystals in organic ground substance can have a number of effects on the tissue. In some cases, it can lead to the formation of hard, brittle structures, such as bones and teeth. In other cases, it can lead to the formation of soft, flexible tissues, such as cartilage. The deposition of mineral crystals can also affect the function of the tissue. For example, the deposition of calcium in blood vessels can lead to atherosclerosis, which is a narrowing of the arteries.