Making the mix takes about an hour and requires the caster to recite the spell while mixing the ingredients in the correct way. Once the mixture is completed it will faintly glow if the spell was successful. The enchantment is triggered by pouring the juice-like liquid into one's palm and then blowing softly on the mixture. It will then catch fire and burn with a brilliant, unnatural green flame. The liquid is immediately consumed by the flame and the flame will stick to the caster's hand. The fire will leave an eerie afterglow in the air that lasts for a couple of seconds if it is moved quickly. The afterglow is harmless.
The glimmer fire acts as real fire and will do damage in the same way a burning torch would do. Things that come into contact with the flame may catch fire, including the witch's clothes. The witch's hand is however completely safe and will just experience a dull warmth. The enchantment is not reliant on concentration. It will keep burning until it is put out like a natural fire, either by dousing it in water or wrapping the hand in a blanket.
Anything put on fire by the glimmer will burn with the same eerie, green flame. It otherwise acts like a natural fire.