There are very few crystals that are true indigo and Iolite Silces are one of them. Here they are as Iolite slices 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. You can use it to strengthen the connection between the third eye and the heart, helping to heal old wounds that are weighing on your chest. Read about the geology of Cordierite.
Dimensions are for the squarish shape.
Iolite slices’ stock is that photographed so we will intuit right one for your needs.