Spinel Kristal (natuurlijke Dubbele Pyramide 3 mm) Weight: ± 0.15 CT. Size: 3 mm Shape: Natural Pyramid Color: Top Pigeon Blood Red Clarity: Clean Luster: Good Origin: Burma Hardness: 7.5 - 8.0 Specific Gravity: 3.6 - 4.0 Refractive Index: 1.71 - 1.76 Chemical Composition: MgAl2O4 , Magnesium Aluminum Oxide Crystal Structure: Isometric