How Does Silver Selenite Compare To Other Types Of Selenite Minerals?

Silver selenite is a rare mineral that belongs to the selenite mineral group, which consists of minerals made up of the element selenium and oxygen. In comparison to other types of selenite minerals, such as gypsum (calcium sulfate), barite (barium sulfate), and celestine (strontium sulfate), silver selenite exhibits several distinct characteristics:

1. Chemical Composition: Silver selenite has a unique chemical composition, with the formula Ag2SeO4, containing silver (Ag), selenium (Se), and oxygen (O). In contrast, other selenite minerals contain different elements, such as calcium, barium, and strontium.

2. Crystal Structure: Silver selenite has a monoclinic crystal structure, which means its crystals have a single axis of symmetry, whereas gypsum has a monoclinic or triclinic crystal system, barite has an orthorhombic crystal system, and celestine has a rhombohedral crystal system.

3. Color: Silver selenite is typically white, gray, or silver in color due to the presence of silver, whereas gypsum is typically colorless or white, barite can range from colorless to various shades of blue, green, yellow, or red, and celestine is pale blue to white.

4. Hardness: Silver selenite has a hardness of 2-2.5 on the Mohs scale, making it relatively soft compared to gypsum (2), barite (3-3.5), and celestine (3-3.5).

5. Occurrence: Silver selenite is a rare mineral that occurs in only a few locations worldwide, including the Erzwies mine in Austria and the Centennial Eureka mine in Utah, USA. In contrast, gypsum, barite, and celestine are more common and widely distributed minerals, found in various geological settings.

Overall, silver selenite stands out among other types of selenite minerals due to its unique chemical composition, crystal structure, and limited occurrence.