6" 1.7LBs Rare Blue Dumortierite Cluster Rough Natural Gemstone Crystal Mineral Collectible Raw Geode Specimen - Sumatra, Indonesia

All our minerals and crystals are carefully measured with digital measuring instruments that provide the high accuracy of numbers/values!

• You will receive exactly this Dumortierite Rough - 154 x 109 x 42 mm / 6 x 4.3 x 1.6 Inches; Weight 785g / 27.7oz / 1.7 LBs; (see photo, some photos are taken wet, the photos are taken under bright light, stand not included)! Photo under LW UV light 365nm was taken with using powerful 10w flashlight with optical UV filter!
• Dumortierite is a boro-silicate mineral that is used as a popular ornamental stone. It has a deep violet to blue color that is very attractive and unusual. Although it is not used as a gemstone due to a lack of clarity, it does have good hardness and a bright color. A variety of quartz called dumortierite quartz is massive quartz colored blue by included crystals of dumortierite. Dumortierite can be misidentified as other ornamental stones such as sodalite, lazurite and lazulite.
• Chemical Formula: AlAl6O3BSi3O18; Hardness: 7; Color: Blue, Pink, Purple; Mineral Class: Dumortierite;
• Dumortierite was named after French paleontologist E. Dumortier. Dumortierite is a relatively hard stone, and its prismatic crystals are most often smaller than 1 mm in size. Dumortierite rates a 7 on the hardness scale, has a vitreous luster, and displays strong pleochroism. This lack of transparency is a result of the fact that it has only one distinct cleavage and an uneven fracture.
• (The above information is provided solely for informational purpose. Kindly note that all stones are offered for decorative purposes only. Please, handle your stones with great care, do not grind or crumble them, do not dip or add them into your food or drink, do not use any parts of them in any elixirs, potions, lotions etc. Always make sure you wash your hands before and after working with your crystals.)