Smoky Quartz (Seer Stone)
Quartz var. Smoky Quartz · Semi-Precious Gemstone / Mineral Specimen
Crystal System
Trigonal; typically prismatic, but this specimen is a water-worn river pebble often called a 'Ema Egg' or 'Window Quartz'.
Mineral Group
Silicates (Tectosilicate)
Chemical Formula
SiO2 (Silicon Dioxide) with Aluminum impurities and natural irradiation
Formation Process
Igneous/Hydrothermal: Crystals form in cooling magma or hot mineral-rich water; the smoky color is produced by natural ionizing radiation from surrounding rock acting on aluminum impurities.
About This Crystal
A frosted, water-worn nodule with a translucent smoky brownish-grey color. It exhibits a polished 'face' or matte surface typical of river tumbled stones.
Physical Characteristics
Color: Smoky brown; Streak: White; Luster: Vitreous to matte; Fracture: Conchoidal (visible if chipped); Specific Gravity: 2.65; Fluorescence: Usually none.
Optical Properties
Refractive Index: 1.544-1.553; Birefringence: 0.009; Pleochroism: Weak to moderate in brown shades; Doubly refractive (uniaxial positive).
Hardness & Durability
Origin Region
Brazil (State of Minas Gerais is the primary source for Ema Eggs); forms in pegmatites and hydrothermal veins.
Hardness & Durability
Mohs Hardness: 7; Toughness: Good; Stability: Stable, though very high heat can cause color fading to citrine or clear quartz.
Care & Maintenance
Safe to clean with warm soapy water; avoid prolonged exposure to direct sunlight to prevent color fading; safe for ultrasonic cleaning if no fractures are present.
Rarity & Value
Common; Value is determined by size, clarity, and the quality of the 'window' cut. Generally inexpensive, ranging from $5 to $30 for specimens of this size.
Special Characteristics
This specimen is a 'Seer Stone', which features one flat polished side to reveal the internal clarity of the frosted river pebble.
Lore & History
Historically used in various cultures as a grounding stone. In modern crystal healing, smoky quartz is associated with the Root Chakra and is believed to neutralize negative vibrations and provide protection.