There are very few crystals that are true indigo and Iolite thumb stones are one of them. Here they are in blue-grey colour.
This crystal creates a strong constitution, ridding the body of fatty deposits. It encourages taking responsibility for yourself, overcoming codependency within your partnerships. can open one to psychic talents and expand them as well. Why not enjoy iolite to calm an over active mind and will assist you in quitting negative addictions. Read about the geology of Cordierite.
Iolite thumb stones are that photographed so we will intuit right one for your needs. Dimensions are for the squarish shape.