Tanga
Rather than being about morals, though, I was thinking that intense desire may have just pushed the person over an edge, of sorts -- from which this act/use of crystals would be seen as purely "useful", and its manipulativeness wouldn't be consciously registered;
There is that.
Or is it ignorance?...
The only crystal id use for love is rose quartz....
That's in the eye of the spell caster. Depends how you're constructing your spell.
For example, to add to aiding of love - I might include... Larimar (blue and white stone) - which fosters speaking and listening with awareness and opening honest communication between souls.
I might have Fire Opal to encourage healthy sexual relationship...
Or perhaps a Herkimer Diamond to promote pure love and harmony with others...
You get where I'm going with this.
And - let me just add a bunch of other uses of Rose Quartz
Eases fear and soothes grief. Fosters inner peace and self-forgiveness, positive self-esteem and body image, induces emotional clearing.
Rose Quartz is a great stone... for "getting your own s*** together" Lol.
Which then presumably would mean - that one was balanced enough to participate in a loving relationship with someone else.