MINERAL OF THE MONTH
April 2018 - Fordite
Fordite, also known as Detroit agate or Motor Agate, is not actually a rock or a mineral. However, it is used in lapidary to make amazing pieces of jewelry, some of which sell for hundreds of dollars. Fordite is actually old automobile paint which has hardened into layers. Decades ago, the process used to paint automobiles was different than it is today. Back then cars were hand sprayed. The color used in the spray booth changed as the production schedule changed. Layers of the enamel paint built up on the tracks and skids on which the car frames were painted. The layers of oversprayed paint became hardened when the car bodies went into ovens to cure the paint. When the build up of paint became too thick, it was removed and discarded.
The original decades-old “Fordite” often display incredibly beautiful and complex, agate-like layers. Eventually people realized these beautiful slag-like layers were patterned like psychedelic agate and could be cut and polished into jewelry.
This spray process has now been automated with an electrostatic process that essentially magnetizes the enamels to the car bodies. This leaves little overspray.
Some say Fordite is no longer produced in car factories, but this is not true. A customer came into my museum who has the job of cleaning the electrostatic painting equipment to remove the still accumulating layers of paint on the equipment. Although much of the modern paint layers are not as colorful as those from decades ago, there is still some jewelry-compatible material being scraped off car painting equipment. In some cases, this new material offers interesting shapes instead of bizarre colors.
Also, some people are making their own Fordite by layering and baking enamel paints in their studios.
If you have acquired a piece of Fordite jewelry, keep in mind that it is a relatively soft material. However, if you do see scratches on the surface of the Fordite, pull out your car wax and a 100 percent cotton cloth and give it a good shine!
Thanks goes to Kyle Koskinen for his photos, video, and samples. I am hoping to find room in the museum to create a “Fordite” display for the 2018 summer season.
CITES
- Rhonda, https://commons.wikimedia.org/wiki/File:2_fordite_jeweries.jpg
- Rhonda, https://commons.wikimedia.org/wiki/File:Beach_Glass_and_Fordite.jpg
- http://www.fordite.com/care.html
Mineral of the Month Archives
May 2007: Rainbow Fluorite
June 2007: Lake Superior Michipicoten Agate
July 2007: Labadorite
August 2007: Rain Flower Agate
Fall 2007: Malachite
December 2007: Nepheline Syenite
January 2008: Native Copper
February 2008: Amazonite
March 2008: Lake Superior Agate
April 2008: Shadow Agate
May 2008: Apohpylite
June 2008: Ocean Jasper
Summer 2008: Marra Mamba Tiger's Eye
September 2008: Mohawkite
October 2008: Mexican opal
November 2008: Prehnite
December 2008: Picture Jasper
January 2009: Sea Shell Jasper
February 2009: Polychrome Jasper
March 2009: Selenite Desert Rose
Spring 2009: Coyamito Agate
July 2009: Obsidian Needles
August 2009: Goethite
September 2009: Banded Iron Formation
Fall 2009: Fairburn Agate
March 2010: Fossilized Dinosaur Bone
April/May: 2010 Kentucky Agate
June 2010: Nantan Meteorite
July 2010: Mookaite Jasper
Aug/Sept 2010: Polyhedroid Agate
Fall 2010: Ammonite Fossil
September 2011: Petoskey Stones
Spring 2011: Petrfied Wood
Winter 2011: Argentina Condor Agate
January 2012: Mary Ellen Jasper
March 2012: Mexican Crazy Lace Agate
June 2012: Moqui Marbles
September 2012: Chlorastrolite Greenstone
March 2013: Jacobsville Sandstone
August 2013: Unakite
November 2013: Skip-an-Atom Agate
April 2014: Tiger's Eye
September 2014: Black Corundum
February 2015: Condor Agate
June 2015: Petoskey Stone
November 2015: Slag
June 2016: Lake Superior Copper Replacement Agates
March 2017: Chert
July 2017: Kona Dolomite
December 2017: Septarian Nodule
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Gitche Gumee Museum.
E21739 Brazel Street
Grand Marais, Michigan 49839

















