moss agate

American  

noun

1. a kind of agate or chalcedony containing brown or black mosslike dendritic markings from various impurities.

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moss agate British  

noun

1. a variety of chalcedony with dark greenish mossy markings, used as a gemstone

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Etymology

Origin of moss agate

First recorded in 1790–1800

Example Sentences

Joel Otterson’s intimate sculptures set moss agate in silver and brass at Ehrlich Steinberg.

From The Wall Street Journal • Feb. 27, 2026

Citrine, aventurine and moss agate are said to attract abundance.

From Los Angeles Times • Mar. 31, 2018

For I had some recollection of having been with our brake-beam-riding right fielder the evening "Lefty" Clancy tried to palm a moss agate out of one of Joe's trays—and got caught.

From Down the Yellowstone by Freeman, Lewis R. (Lewis Ransome)

Before Jack was aware what the man was up to he had grabbed from his finger the curious moss agate emblem.

From Jack Ranger's Western Trip Or, from Boarding School to Ranch and Range by Young, Clarence

It was one with a big moss agate, with the outline of a pine tree on it, and a lot of emeralds and rubies set around its center.

From Jack Ranger's Western Trip Or, from Boarding School to Ranch and Range by Young, Clarence