“Water sapphire” has been used for iolite, but does not make it sapphire. The mineral's correct name is the starting point for a jewellery description.

What is iolite?

Iolite is gem-quality cordierite. Strong pleochroism means it can appear blue-violet, pale yellow or nearly colourless along different directions. This depends on orientation and differs from alexandrite's colour change between light sources.

Why orientation matters

Request a front view and a moving demonstration. Observe the colour in its intended jewellery position, not just the best hue during rotation. View paired earrings together: different orientations can create different impressions.

When comparing with another blue gem, start with appearance and dimensions, then read each identification. There is no reason to retain a misleading name merely because it is familiar.

Historical stories

Legends about navigators using iolite are interesting stories but cannot authenticate a gemstone or establish an object's provenance. For a collection piece, request documents about the actual specimen.

The invoice should state correct identity and treatments. Read our blue gemstone comparison, or request gemmological identification for an unknown stone.