National Museum of Natural Science

Due to ferric ions contained with the crystals, heliodor appears pale lemon yellow to yellow or golden yellow. It possesses a glass-like luster and measures 7.5-8 on the Mohs scale of mineral hardness. In general, it is golden yellow and the highest value heliodor is free from impurities. In this exhibition are one cut specimen and one rough specimen, both from Tajikistan. The rough, hexagonal columnar heliodor specimen weighs 448 grams and the largest crystal measures 5.7 centimeters in length. Along the cylindrical surface of the crystal are lengthwise growth lines. The faceted specimen is approximately 2.5 centimeters in diameter and 51.5 carats. 

Heliodor