Colorful Brazilian Agate standup
The agates from Brazil are mostly mined from decomposed volcanic
ash and basalt from the late Permian age (248-275 million years ago)
In Rio Grande do Sul the "agate mines" are normally just plowed fields
in which loose agates are found and collected. Brazilian agates are
very colorful stones with some of the most beautiful inclusion and
structures imaginable. Agate is very hard and takes an excellent polish.
Reference from Spritrockshop
What is an Agate?
An Agate is a cryptocrystalline variety of silica, chiefly chalcedony, characterized by its fineness of grain and brightness of color. Although agates may be found in various kinds of rock, they are classically associated with volcanic rocks and can be common in certain metamorphic rocks.
Measurements: 3 3 /4 x 2 3/4 x 2 1/4 . Weight:
This agate is the natural color.