Rock Family: Igneous Rock (Rhyolite)
Major Minerals: Feldspar, Quartz
Minor Minerals: Natural Glass

Color: All colors
Gravity: 2.4-2.6
Hardness: 6.5-7
Fluorescence: None
Texture: Porphyritic
Transparency: Opaque

Where does Rhyolite come from?

Rhyolite is found in several locations around the world.  Here are a few of the deposits of interest for the metaphysical and collectors’ market:

  • Chrysanthemum Stone – New Zealand
  • Jaguar Stone and Leopardskin Jasper – Mexico, Peru
  • Kambaba Jasper / Crocodile Jasper – Madagascar
  • Nebula Stone – Mexico
  • Ocean Jasper – Madagascar
  • Rainforest Jasper – Australia
  • Thunder Egg – Mexico and the United States

What is a Rhyolite?

Rhyolite Placeholder
Rhyolite

Rhyolite is not a mineral, but rather an igneous rock. As an easy way to understand the difference, think of rocks as being like cookies and minerals as being the ingredients which make up those cookies. Many different minerals are used to create a rock!  Many Rhyolites have a high silica content which gives them a high shine when polished.  A few colorful varieties are sold on the market, often labeled as a “Jasper.”

How is Rhyolite formed?

Rhyolite is a type of extrusive igneous rock, formed on the surface of the earth by molten magma due to a volcanic eruption. There are five types of igneous rocks created by lava: Basalt, Obsidian, Rhyolite, Trachyte, and Andesite. Other types of igneous rocks, such as Granite, are created by processes deep within the earth. Rhyolite is a relatively rare volcanic rock, almost exclusively found in the interiors of continents. Most Rhyolites are porphyritic and contain large Quartz crystals or other varieties of crystals in an extremely fine-grained matrix. This indicates that these crystals were already being formed before the lava flowed onto the surface. Jaguar Stone is a popular name given to spotted Rhyolite found in North and South America.

How is Rhyolite mined?

Rhyolite is mined at its primary deposit.  It is often found with Obsidian and Pumice.

Why is Rhyolite sometimes mislabeled as Jasper?

There are many stones and minerals sold on the market as “Jasper.”  Some of these are “true Jaspers,” a spotted Chalcedony, for example Brecciated Jasper.  But many others are attractive igneous rocks, usually a colorful Rhyolite.  Oftentimes miners and sellers aren’t educated in the finer points of geology, so whatever name is easier to communicate or is considered more marketable will be used.  The simple truth is that a “jasper” is easier to sell than “rhyolite.”