ClassicGems.net

Emerald  (variety of Beryl)

Discovered (Prehistoric);   IMA status: Emerald - Not Valid; Beryl - Valid

Classification

Mineral Classification:

Silicates

Strunz 8th Ed. ID:

8/E.12-10

Nickel-Strunz 10th Ed. ID:

9.CJ.05

9 : SILICATES (Germanates)
C : Cyclosilicates
J : [Si₆O₁₈]₁₂- 6-membered single rings (sechser-Einfachringe), without insular complex anions

Related to:

Beryl Group: Beryl, Bazzite, Indialite, Stoppaniite, Pezzottaite. Beryl Series

Crystal Data

Crystallography:

Hexagonal - Dihexagonal Dipyramidal

Crystal Habit:

Crystals prismatic to tabular, may be complexly terminated by pyramids, to 18 m and 180 tons. Also radial, trapiche, columnar; granular to compact.

Twinning:

Rarely

Physical Properties

Cleavage:

[0001] Imperfect

Fracture:

Conchoidal to Uneven

Tenacity:

Brittle

Hardness (Mohs):

7.5 - 8.0

Density:

2.68 - 2.80 (g/cm³)

Luminescence:

None

Radioactivity:

Not Radioactive

Optical Properties

Color:

Bluish Green to Green, "Emerald Green"

Transparency:

Transparent to Translucent

Luster:

Vitreous, Resinous

Refractive Index:

1.572 - 1.600  Uniaxial ( - )

Birefringence:

0.005 - 0.010 (varies by locality)

Dispersion:

0.014 (low)

Pleochroism:

Weak to Distinct

Occurances

Geological Setting:

In granites and granite pegmatites, rarely in nepheline syenites. Also in mafic metamorphic rocks, low- to high-temperature hydrothermal veins and in vugs in rhyolite.

Type Locality:

Prehistoric

Year Discovered:

Prehistoric

View mineral photos:

Emerald Mineral Photos and Locations

More Information

Mindat.org (Emerald)
Mindat.org (Beryl)
Webmineral.com (Beryl)

Emerald is the green color variety of the Beryl family of minerals that includes Aquamarine (blue), Bixbite (red), Goshenite (colorless), Heliodor (yellow), Morganite (pink) and Pezzottaite (pink/red). Emerald gets its green color from traces of chromium added to the basic Beryl formula.

The name Emerald is from the Greek smaragdos (green) through the Middle English word esmeralde. The name Beryl is from ancient Greek meaning "precious blue-green color of sea water" stone which was originally applied only to Aquamarine but was later used for the Beryl family.

Emerald is found in many locations around the world. Probably the best known is the Muzo Mine in Colombia. This mine produced a 16,020 carat crystal! Emeralds from this location are generally considered the best color for Emerald. Emerald was mined at Queen Cleopatra's Ancient Egyptian emerald mine.

Emerald gems for sale:

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