Specimens Nitratine or soda niter is one of the few nitrate minerals that is available on the mineral markets. Nitrates are not all that commonly found due to their general ease in dissolving in water. In fact some solid nitrate crystals will even become liquid by removing water from the moisture in the air, a process called deliquescence . Nitratine is deliquescent and is very soluble in water and thus care should be taken to preserve valuable specimens in air tight containers with desiccant. Most nitrates are found in arid, desert regions such as around the Persian Gulf or found as efflorescences on dry cave or mine walls.
Nitrates are similar to carbonates.
The nitrogen is surrounded by three oxygens and forms a tight flat triangular NO 3 ion group just like the carbonate triangular CO 3 ion group. Thus nitrates are placed in the Carbonate Class of minerals. But there are some differences. These differences show up in a greater difficulty in breaking apart the nitrate ion group as is usually an easy task for acids with the carbonate ion group, greater solubility and a much less diverse subclass of minerals. Nitratine is most similar to the trigonal carbonates or those carbonates that belong to the Calcite Group , specifically magnesite , rhodochrosite , siderite , smithsonite , sphaerocobaltite and of course calcite and some rarer members.