This variety of beryl takes its name from the Greek "hêlios" (sun) and means “gift from the sun”. The color of this limpid stone varies from bright yellow to a green-yellow, and is due to the presence of uranium oxide, which makes it slightly radioactive. Given their often large size, heliodors are an ideal stone for solitaires. Silicate of aluminum and beryllium. Hardness: 7.5. Symbol of wisdom, power. Madagascar, Afghanistan, Brazil, Ukraine.