system
A chat on 4chan
human
You’re also right about them going higher on price. I got mine maybe 5 years ago at no more than 300 for the biggest…now it’s around 6-800 minimum. I’d say the larger ones are great at holding and increasing their value.
gpt
The four main uses of gems and crystals are:
>personal talismans
>programming environmental energies, such as programming each room in your house with different large crystals
>spellcasting
>healing
There are many methods to use them in each of these categories. 
A good quality gem functions as a basic planetary talisman, or chakra talisman, all on it's own. Placing a paper talisman with a gem will amplify the power of that talisman. 
Crystals can be programmed with chanting plus visualization, or by a mantra. 
Some crystals will powerfully activate chakras, and remove blockages from them over-time. 
Methods of crystal healing typically consist of finding a crystal purported to have a specific healing affinity, and then programming it with that healing intent, and briefly applying the crystal every day to the afflicted part. Presumably a celestial spirit, or a crystal spirit, or the crystal vibrations, or simply the power of your faith and willpower, is what cause the healing. Some people will read a healing scripture verse as well, making it somewhat like faith healing. It might also be that a simple healing ritual performed daily redirects subtle healing energies for healing. 


Real inflation is closer to 5-10%, and many gems and crystals have increased in price 10% average for the past several decades, which outperforms SP500 and gold. The problem is it can be hard to sell second hand for full price, unless you already have a store.