Moss Agate

Big Photo

Indonesia
17.45 carats
© gemselect.com

Moss agate is a colourless, translucent Dendritic Agate variety of Chalcedony with inclusions of green hornblende (or chlorite) in moss-like patterns (therefore the name).

Moss agate, although primarily green, can also show brown and red patterns due to the oxidation of the iron in the hornblende/chlorite.

The name 'Agate' is generally accepted even though the stone is not banded as a true agate should be.

Moss Agate Gemstones by Colour

This table shows the variety of hues this gemstone can be found in. Click on a photo for more information.
 

Moss Agate Gemstones by Size

This table shows distribution of Moss Agate gemstone sizes that are listed on this site. This can give a good indication as to the general availability of this gemstone in different sizes.
Contributed photos
Lightest:17.1 cts
Heaviest:58.40 cts
Average:24.27 cts
Total photos:12
Do you have a larger Moss Agate? Why not upload a photo?
17.10ct to 21.23ct21.23ct to 25.36ct25.36ct to 29.49ct29.49ct to 33.62ct33.62ct to 37.75ct37.75ct to 41.88ct41.88ct to 46.01ct46.01ct to 50.14ct50.14ct to 54.27ct54.27ct to 58.40ct
General Information
A variety or type of:Dendritic Agate, which is a variety of Chalcedony, which is a variety of Quartz
Chemical Formula
SiO
 
2
Walter Schumann, Gemstones of the world (2001)
Photos of natural/un-cut material from mindat.org
Physical Properties of Moss Agate
Mohs Hardness6.5 to 7
Walter Schumann, Gemstones of the world (2001)
Specific Gravity2.58 to 2.64
Walter Schumann, Gemstones of the world (2001)
Cleavage QualityNone
Walter Schumann, Gemstones of the world (2001)
Optical Properties of Moss Agate
Refractive Index1.530 to 1.540
Walter Schumann, Gemstones of the world (2001)
Birefringenceup to to 0.004
Walter Schumann, Gemstones of the world (2001)
PleochroismAbsent
Walter Schumann, Gemstones of the world (2001)
DispersionNone
Walter Schumann, Gemstones of the world (2001)
Colour
Colour (General)Translucent to white with green veins/streaks.
Gemdat.org, Management Team (2012)
Causes of ColourGreen streaks are inclusions of green amphibole or chlorite-group minerals.
Gemdat.org, Management Team (2012)
More from other references
TransparencyTranslucent
Walter Schumann, Gemstones of the world (2001)
Fluorescence & other light emissions
Fluorescence (General)Variable, cannot be used for a diagnosis
Walter Schumann, Gemstones of the world (2001)
Crystallography of Moss Agate
Crystal SystemTrigonal
Walter Schumann, Gemstones of the world (2001)
HabitMicrocrystalline
Walter Schumann, Gemstones of the world (2001)
Geological Environment
Where found:It occurs as filler in fissures or as pebbles.
Walter Schumann, Gemstones of the world (2001)
Inclusions in Moss Agate
Chlorite, hornblende inclusions in moss-like pattern. - Gemstones of the world, Walter Schumann, 2001, p 130
Further Information
Mineral information:Moss Agate information at mindat.org
Copyright © Jolyon & Katya Ralph 1993-2018. Site Map. Locality, gem & photograph data are the copyright of the individuals who submitted them. For more information please contact the . Gemdat.org is an online information resource dedicated to providing free gemmological information to all.