Kyanite is a gemstone that you will rarely encounter in the typical jewellery store. Most people have not heard of kyanite, as it is infrequently used in jewellery. It is an "exotic" gem. Perhaps that is what makes it so interesting?
If you are interested in kyanite as a gemstone or in jewellery, the best place to find it is in artisan jewellery stores or in jewellery stores that are associated with a mineral dealer