I've read borax is used for cleaning, and very many other purposes as well (has been for thousands of years). I've also been using about 1/3 tsp a day, for about 2 weeks, in my salt water solution and drinking it, as a source of boron (an essential trace mineral, supposed to be effective for taking fluoride, and heavy metals, out of the body). It is actually about 50% less toxic than common sea salt, but authorities have for very long been describing it as extremely toxic and the kind you should under no circumstances consume or even get onto your hands (Australia actually has selling it banned in the country because someone decades ago made a mistake of trying to spread it as a treatment for many illnesses in mass and thus contacted medical companies - the result was it was banned because it actually helped against and cured many illnesses).
It's also used as plant fertilizer but the amounts used have to be very small as too much can harm or kill the plant, but if there's too little in the soil then plants can't grow right either.
The substance itself is naturally occurring, it is not artificial, not synthesized. It's dug from the ground. One major deposit was in USA I think, and another is in Turkey. Supposed to be some ancient lake or sea sediment, a salt really.
