Important: As a natural earth mined volcanic glass this material can be sharp and is not recommended for children.The Fantasia brand of Assorted Obsidian (also known as volcano glass) rough you are ordering is 100% natural and imported by the ton directly from Mexico to Fantasia Mining's USA rock yard. This material has a beautiful deep color and is perfect for tumbling, polishing, cabbing, cutting, wire wrapping or keeping in it's natural form as a specimen. Your order will contain multiple pieces of this spectacular material of varying natural sizes and shapes as shown in the images which is equal to or greater than the weight purchased.VERY IMPORTANT: This is rough natural material which means you are receiving it exactly how it came out of the ground and there may be sharp edges. All pictures were taken with the stones being wet which helps to show the materials true colors and clarity. It may not have the same appearance when dry unless it has been polished, tumbled, or cabbed. If you have any questions about this feel free to contact Fantasia Mining prior to purchase so we can ensure you will be completely satisfied with your order.Scientific Properties:Group: Silicate: UnclassifiedChemical Formula: Na2O.CaO.6SiO2Specific Gravity: 2.21 - 2.60Moh's Hardness: 5.0 - 6.0Refractive Index: 1.450 - 1.550Metaphysical Properties:Primary Chakra: RootAstrological Sign: Sagittarius, ScorpioVibration Number: 1