Moqui Marbles

Moqui Marbles are hematite concretions that form in the sandstone's of southern Utah and Arizona.

They formed as ground water moved through the sandstone dissolving the iron until the water was super saturated with dissolved iron and the iron starts to come out of solution in the form of hematite.  Because this occurs under the sandstone there is equal dimensional pressure causing the iron to form spheres or bubbles, just like when a soap bubble is blown.  As the concretionary bubble develops it encases sandstone within the bubble.  Because this process is formed by water running through sandstone, other similar structures also form.  Pipes, resembling cast iron pipes develop. 

They get their name from the Moqui Indians that inhabited the area they are found in, and like the Anasazi Indians, they vanished without a trace.  The mystery of the vanishing Indian tribe seems to add to the mystic of the marbles.

There is also a Hopi Indian legend that insinuates that these round concretions were used to play games.  Other than a legend there is little archaeological evidence to support this claim.

Moqui marbles are very prolific and range in size from 1/16 inch to over 1 foot with reports of them over 12 feet in diameter.  Most are not larger than a small apple.  Many are very rounded but other shapes are common.  Flying saucers, gourds, pineapples, discs, and a number of other shapes are popular with collectors.

These oddities seem an unlikely candidate for lapidary but they have been used in several different ways.

They can have holes drilled  into small ones for beads.  The textured exterior makes for a great natural crude-looking bead or they can be cut and used as a cabochon without polishing them.

Another use is to cut a larger one in half and place one side next to a fire place as a match striker.  They blend into the rustic setting as nicely as they do a more elegant setting.

There are federal laws protecting Moqui Marbles now so field collecting is not available anymore.  They do come off of private land so most rock shops still have them for sale.  As private lands run out of them the prices will continue to increase as there is a high demand for them.

Moqui Marbles became even more famous when NASA geologists discovered them on Mars using the land rover Opportunity.  Moqui Marbles are caused by free-flowing ground water proving there was once running water on Mars.  There is some evidence that algae or bacteria may help in the forming of these concretions sparking more research and theories about these hematite concretions.

One researcher dubbed them “blueberries” because of their size and shape.  This is unfortunate as it has lead to a lot of confusion as there are azurite concretions from the LaSal Mountains in south eastern Utah that are called blueberries because they are the size and shape of blueberries—and the right color, BLUE.

New Agers have given Moqui Marbles “spiritual” characteristics and even dubbed some male and female making these as the only known rocks with a gender.

Some Moqui Marbles are vapor coated with titanium to give them a very sparkly and colorful

appearance.  This is the same process that is used to make “aqua aura” from quartz crystals.  These have been sold by unscrupulous or uneducated dealers under the trade name “boji stones” and as natural having spiritual and/or medicinal properties.