Clear quartz
Powerful stone.
It helps with concentration, increases inspiration and creativity.

The chakras are related to the endocrine system.

Purple, the crown chakra is our connection to the universal energies.
Indigo, the 3rd eye chakra is for forgiveness and compassion.
Blue, the throat chakra is for physical and spiritual communication.
Green, the heart chakra is for love and a sense of responsibility.
The Chakrayellowsolar plexus is for power and ego.
Orange, the sacral chakra is associated with emotions and sexuality.
The root chakra red is for rooting and survival.