Fire Quartz Skull

Chakra: Root, Sacral, Solar Plexus, Heart, Throat, Third Eye, Crown
Element: Fire
Known As: The Universal Crystal
Planet: Sun
Rarity: Common
Resonant Number: 4

Category: Silicate Mineral
Chemical Formula: SiO_{2
Crystal Class: α-Quartz: Trapezohedral; β-Quartz: Trapezohedral (Class 6 2 2)
Crystal System: α-Quartz: Trigonal; β-Quartz: Hexagonal
Dana Classification: 75.01.03.01 (Tectosilicates)
Name: Quartz
Space Group: α-Quartz: P3221 (no. 154), β-Quartz: P6222 (no. 180)
Strunz Classification: 4.DA.05 (Oxides)
Synonym: Agate, Amethyst, Aventurine, Carnelian, Cat's Eye, Chalcedony, Chert, Chrysoprase, Citrine, Flint, Hornstone, Jasper, Moss Agate, Plasma, Prase, Rock Crystal, Rose Quartz, Sapphire Quartz, Smoky Quartz, Tigers Eye
Unit Cell: a = 4.9133 Å, c = 5.4053 Å; Z=3}

Birefringence: +0.009 (B-G interval)
Cleavage: {0110} Indistinct
Common Colors: Colorless, Various depending on inclusions
Crystal Habit: 6-Sided Prism, Hexagonal Terminations, Drusy, Massive, Microcrystalline
Diaphaneity: Transparent to Opaque
Formula Mass: 60.083 g·mol^{−1
Fracture: Conchoidal
Luster: Vitreous to dull
Melting Point: 1670 °C
Mohs Hardness: 7
Optical Properties: Uniaxial (+)
Pleochroism: None
Refractive Index: nω = 1.543–1.545, nε = 1.552–1.554
Specific Gravity: 2.65
Streak: White
Tenacity: Brittle}