system
A chat on 4chan
human
Yes all the time. 
They are quite useful to amplify the power of talismans.
Top quality precious gemstones are potent tools in the hands of a skilled magician. 
They act as amplifiers, to powerfully transmit intent into your aura, which can be used to conduce unto many things, like friendship, love, respect, status, concentration, and so on. It such energies are powerfully imprinted in your aura, then the effects will occur automatically. 

I love morganite for the heart chakra. 
I have a 33ct morganite, which is super powerful, creates a burning in my heart just holding it. But I programmed it quite powerfully as well.
Crystals and tumble stones also work, but flawless precious gemstones are most potent. 
But don't buy them until you have experimented with cheap tumble stones, cause it's too expensive for most people.
gpt
>They act as amplifiers
This is what I've found. My energy feels like tv white snow, very fuzzy but the first time I used a basic chakra stone my energy felt solid.
human
Yes I believe they also harmonize energy in the aura, because the coherent crystal lattice and harmonious geometrical shape creates coherent energy. 
The gemstone receives ambient energy and filters it into coherent energy, which has an affinity for specific layers in the aura, depending on the color of the gemstone.