I honestly cant remember - we just save a lot of these kinds of pictures for ideas on what to do with our own gems (this particular idea would not be possible for us though as we produce mainly blue sapphire). The purple stone makes me think this particular one might not be (amethyst??) but I have seen similar "rainbow" effect bracelets done all in sapphire - very spectacular. I suppose it might be difficult to get something like this in untreated stone if that was important to you but it would not be impossible as sapphire does come in a huge range of colours.
love this thread! it showcases some more unusual and unique ideas for diamond bracelets rather than the typical tennis all-diamond styles we so often see! as much as i like sparkly diamonds, those always remind me just a little bit of grandma.