Moss agate is an un-banded (and therefore not a true) agate. It is a chalcedony with dendritic inclusions of other, typically green, minerals forming filaments and patterns that are suggestive of moss. Occasionally brown coloration or red spots due to iron oxide will also be found in moss agate.
A cabochon of moss agate from Australia with black dendritic manganese oxides embedded in milky-white chalcedony (quartz). Moss agate is a semi-precious gemstone. It is a variety of mineral quartz.
Photo By Tiit Hunt – Estonian Museum of Natural History, CC BY-SA 4.0, https://commons.wikimedia.org/w/index.php?curid=81096800
A cabochon of moss agate from Australia with black dendritic manganese oxides embedded in Australian Moss Agate cabochon
Photo By zygzee from Coarsegold, US – Australian Moss Agate Opus01, CC BY 2.0, https://commons.wikimedia.org/w/index.php?curid=84652497
Moss agate can be found in India, Brazil, Uruguay, central European countries, and the United States (mostly Montana), although some of the best examples are found in India. It is often tumbled and sold as beads or cabochons for jewelry. The city of Mocha in Yemen was once a source for the this stone, lending the alternate name ‘Mocha Stone’.
Those who believe in crystal healing and that stones and minerals have spiritual properties believe it has the properties of stability, persistence, grounding.
Moss agate has been used for art and jewelry since ancient times. Several examples are below.
A moss agate ring stone portrait bust of a bearded man facing a larger portrait bust of a woman. Roman, 2nd century A.D. Most interesting about this piece is that the woman’s coiffure can be used to date the item, pointing to the time of the Younger Faustina, the wife of Roman Emperor Marcus Aurelius.
A moss agate ring stone of a man riding a tortoise. Roman, 1st century B.C. – 3rd century A.D.
A chatelaine made of gold and moss agate stones. A chatelaine hung from the waist and was designed to hold sewing, writing, or toilet implements. British 1750-1760.
A beautiful stem cup made of enamel, silver and gorgeous moss agate. South German, probably Augsburg
A nécessaire containing moss agate panels mounted in gold and set with diamonds, rubies and emeralds. The moss agate in this piece very strongly resembles moss or ferns. These examples of the stone likely came from Central Europe. A nécessaire usually contained various toilet implements, but this one, made by watchmaker James Cox, also contains a watch and automaton on the inside.
Check out our selection of moss agates for sale.
Top image is Moss Agate Opals, photo by Aisha Brown – https://www.flickr.com/photos/[email protected]/28361163809/, CC BY-SA 2.0, https://commons.wikimedia.org/w/index.php?curid=66225173