Kitties LOVE Selenite. So do snakes and lizards. Unless you live in an old house that was never renovated, or below the equator, you probably do too.
If I had a piece of selenite I liked, I might make it into a candle holder, as they are very resistant to heat. Even selenite rendered to anhydrite will take on humidity to just render back to selenite, so the heat of a candle won't really matter. It is the calcium/sufate ph balance that makes it stable, not the water. That is basically what it is Calcium cancelling the acidic nature of naturally occuring sulfuring acid. The reaction trapped water and now you have selenite.
It is naturally warm, like all forms of gypsum.
This makes it useful for being a comfy zone for relaxation and peace. It is not really a "stone" per se, but a mineral; a sulfate, the most common. Made of Sulfate, Calcium, and Water. Take the Water out, and you get Anhydrite. You can take it apart with your hands, so be careful letting a kitty with claws near it. They could easily take a chunk out. You can get carving tools and simply carve at selenite like a block of soap. And it is not a stone, it is a alkali mineral composite, so there is no reason to keep it in any given shape unless you simply like it.
Your car battery (if leaden) probably has the makings of Selenite in it, if it got to the right temperature. Do not bury this stone unless you realize that (depnding on the ph balance of the earth it is in) that it may partially render back to the soil. It is HIGHLY water soluble. Don't even think of that.
I hear this "stuff" about Selenite being the only thing that can reprogram or cleanse quartz, but this is (in my experience) bunk. There are tons of ways to do this in simple kitchen chemistry. Though I dislike the word "reprogram" in relation to minerals and stones.
Sulfate was the most common subfumigant there is. Even "burning sage" is actually burning sulfur. Epson salts are the same. The nature of Sulfur is cleansing.
Sulfate is the salt of Sulfuric Acid. Your Selenite is essentially calcium and "brimstone" bound to atomic water. Roast this with Zinc, and you get the White Vitriol of the Alchemist. DO NOT TRY MINERAL ALCHEMY AT HOME KIDS, unless you know what you are doing.
One of the greatest uses for this was by Abu Mansur, the famous Persian Alchemist and Physician: He advised to heat Selenite on low heat, until it become a white "lime" (anhydrite cause all the water is gone) and then mix it with the white of a egg (cause it breaks down very easy). This plaster is useful for making casts and setting bones. This same plaster was the original plaster of paris. "Selenite" plaster of paris is *very* nice to work with but you have to ask for it by name.
We dont use actual egg anymore as the binder and usually lower quality "industrial gypsum" (because of the greater demand and ability to refine it), but this same type of material (not as hard) is what "sheet rock" or "drywall" is made of.
Your home is probably full of selenite. Hopefully you love that!