Enjoy the summer! We may be away, expect a little longer for us to reply to inquiries
Rhyolite usually has a similar composition and appearance to granite. Rhyolite forms as a result of volcanic eruptions, while granite forms when magma solidifies beneath the surface of the earth. Another difference is granite includes muscovite, and rhyolite does not. Rhyolite is found all over the planet and it takes many different forms depending on the rate at which the lava cooled. The hardness and toughness of the rock is variable, depending on its composition and the rate of cooling that produced it, actually obsidian and pumice are two very different types of rhyolite.
Our favorite rhyolites are:
Chihuahua Mexico is where much of the Birds Eye rhyolite on the market is mined. It is found in a valley without vegetation and it takes hard rock mining to get to this particular rough. This form of rhyolite has spherical formations in red, cream, gray and pink colors.
Mexican Fire Opal
Rhyolite can have vugs filled with gemmy transparent orange fire opal. This material can be cut into beautiful cabochons and is sometimes faceted when it is transparent or even translucent. Famous deposits of this type of fire-opal-in-rhyolite are found in Mexico. The pendant shown in the picture here is a Mexican Fire Opal, the rhyolite matrix around the fire opal adds much interest to this piece.
Hickoryite and Wonderstone
This is a variety of rhyolite displaying bands of red, brown, tan, purple or yellow. These ornamental stones are found in large deposits. It is sometimes called "Candy Stone", many names are given to it based on the place where it was collected. This variety in particular has varying degrees of coarseness and sometimes is very soft making it hard to polish.
Leopardskin rhyolite has orange and red coloring among yellows, green and darker brown or blacks in swirls or non-uniform bands. There can be orbicular markings among the coloring. It is often referred to as Leopardskin Jasper or Leopardskin Agate, but it is a rhyolite.
This green form of rhyolite is often mistakenly called, Rainforest Jasper, when it's not a jasper at all.