Celestite– A colorless, white, gray, blue, green, yellow orange, reddish brown color or pale blue crystal with a Mohs hardness of 3-3.5** and resonates with the Air element. It works with the Chakras: 4th, 5th, 6th, 7th and higher. It has an orthorhombic crystal system and grows in a prismatic and tabular growth pattern. The blue gray variety is found in Madagascar but can be found in Europe and the USA.
To be continued!
**Source: The Book of Stones by Robert Simmons and Naisha Ahsian