This gorgeous Rainbow Moonstone sphere measuring 8.8cm in diameter displays a creamy white translucence and flashes of glowing bright blue. When exposed to the light, flashes of lunar white, like moonbeams, glow from within the stone alongside sparkling blues and rainbow colours. Speckles of bright Black Tourmaline add a stunning contrast to the stone's ethereal colours, which glow brilliantly due to the careful polish upon the moonstone's surface. What Is Rainbow Moonstone Made Of? Rainbow Moonstone is a plagioclase feldspar mineral, and is thus a form of Labradorite. Confusingly, it is not technically a traditional moonstone: instead, it can be referred to as White Labradorite. The Difference Between Moonstone And Rainbow Moonstone Traditional moonstones and Rainbow Moonstones are very similar but crucially different. Both stones are feldspar minerals and have the same hardness on the Mohs scale; both tend to have a creamy white base and both display a glowing, pearly sheen that looks like moonlight glowing from within the stone (a phenomenon known as adularescence). However, the two stones are two different types of feldspars: whilst traditional moonstone is an orthoclase feldspar, Rainbow Moonstone is a plagioclase feldspar like Labradorite. The signature flash of colour, like moon shine, from within moonstone is caused by Albite inclusions in traditional moonstone, however this adularescent effect is caused by a similar mechanism but different chemical inclusions in Labradorite, and thus Rainbow Moonstone as well. The inner glow of Rainbow Moonstone is caused by the refraction of light between layered minerals: this is the same mechanism that leads to the iridescent Schiller Effect in Labradorite. Furthermore, the adularescence in traditional moonstone manifests in flashes of white, whilst the adularescence in Rainbow Moonstone manifests in spectacular flashes of blue, and sometimes other colours of the rainbow (hence the name Rainbow Moonstone). Consequently, these stones are strongly related but also very different.