A "certain mineral"? Colloidal silver, perhaps...?
If so...Silvermedicine.org - Colloidal Silver
I'm guessing that effects from smoking the residue hasn't been tested, but I'll pass. I'm just not a cavalier as I used to be.
I've never had a problem with the light technique though. (other than the first time, when I made few hermies instead of just one) Perhaps a longer interruption, or more lumens, or both...? I just sneak her out for a few nights, about 5-10 minutes, and sneak her back in. 3 - 23 watt CFL's.

Also...if you have the room to do so, no need to cull her so she won't pollinate everything. If you cut her back and re-veg her, (re-veg link is in my sgnature) she'll resume normal vegetative growth, and if no added stresses, no future nanners. Any nanners that were left after trimming shrivel-up and die. It's like hitting the "reset" button. Also provides boatloads of new shoots which are great for clones.
Rusty Trichome Reviewed by Rusty Trichome on . Colchicine treating I've read from a few sources that crushing Colchicine tablets or extracting the raw colchicine from the winter crocus bulbs and soaking your seeds in it is the most preferred and used method to feminize seeds....anyone have any input as to this method of feminization? Rating: 5