Pink to a grey-white variety of Tenebrescence Sodalite: Na8Al6Si6O24(Cl2,S)
This stone changes colour in sunlight which is why it is referred to as tenebrescent (another stone that does this is Tugtupite).
Hackmanite is thought to be helpful for those who suffer from harassment, fear, and apprehension. It is believed to stimulate audacity and strengthen self-esteem while encouraging feelings of happiness, confidence, and contentment.
Hackmanite is sometimes referred to as the chameleon stone and depending on the actual colour state of the stone, it is thought to provide different metaphysical abilities and healing powers.
It is an excellent stone for the throat, third eye, and heart chakra.