Selenite
Selenite is the transparent crystalline variety of gypsum — calcium sulfate containing water within its crystal structure. It has a clear, delicate appearance and a vitreous to pearly lustre. Its crystals can form flat plates, elongated crystals and striking clusters.
Gemological properties
| Property | Information |
|---|---|
| Material | A sulfate mineral; a variety of gypsum |
| Chemical formula | CaSO₄·2H₂O |
| Crystal system | Monoclinic |
| Colour | Usually colourless; inclusions may impart other hues |
| Transparency | Transparent to translucent |
| Lustre | Vitreous to pearly |
| Hardness | 2 on the Mohs scale |
| Specific gravity | Approximately 2.31 |
| Refractive index | Approximately 1.521–1.530 |
| Birefringence | Approximately 0.009 |
These values refer to the crystalline gypsum that makes up selenite.
Selenite and satin spar
Transparent selenite should be distinguished from the fibrous variety of gypsum known as satin spar. They share the same chemical composition but differ in appearance: selenite forms transparent crystals, while satin spar has parallel fibres and a silky lustre, sometimes displaying a cat’s-eye effect.
Sources around the world
Selenite crystals are known from Mexico, the United States, Spain, Italy, Poland and Australia. One of the best-known sites is Mexico’s Naica mine, where enormous gypsum crystals developed. In New Mexico, USA, selenite crystals also form around Lake Lucero as mineral-rich water evaporates.
Care and cleaning
Selenite is very soft and scratches easily, so it should be stored separately from harder stones and objects that could damage its surface. A soft, dry brush is recommended for gentle cleaning. Avoid soaking it in water, which can damage the crystal surface because of its solubility, and avoid heat, which can change the gypsum structure through the loss of its bound water.
Spiritual and symbolic meaning
Selenite is associated with inner clarity, energetic cleansing and openness to subtle levels of awareness. It is linked symbolically with the third-eye and crown chakras, representing attention to intuition, connection with the higher self and deeper reflection during meditation.
In spiritual practice, it serves as a symbol of releasing emotional burdens and restrictive patterns, and creating a quieter, clearer inner space. Some people use its crystals and wands in rituals intended to cleanse the aura and surrounding space, or alongside other stones with the intention of encouraging harmony and attunement.
These meanings belong to the realm of belief and symbolism. They can give jewellery personal significance, but they are not proven gemological properties or a promise of healing, protection or a change in health.