A Pinto horse has a coat color that consists of large patches of white and another color, usually browns. The color pattern existed in prehistoric times, and has been specifically bred by various cultures throughout history. Although pinto coloration is rare in the wild, people have always had an eye for animals of unusual colors.The Pinto horse originated in Spain and was introduced to North America by Spanish and other European explorers. The Spanish explorers brought over Barb horses that had been crossed with other European breeds including Russian and Arabian strains, which are thought to give the horses their color patterns. When the Spanish herds were brought to North America, these horses mixed with the wild horses and were later domesticated by the Native Americans.
Later, when the West was being tamed, the pioneers had to cross their refined European horses with the wild herds to develop a stockier and heavier muscled horse that would be more suited to the rugged and arduous conditions. Often referred to as piebald or skewbald horses in literature about the Wild West, the Pinto horse was a favorite among American cowboys and Native Americans. So would it be any different for a miner’s find to be named for the famed wild American horse. 
A miner’s find among pockets of varying types of Turquoise, a new and rare discovery in the Gila Wilderness Area of Southern Arizona is Wild Horse Magnesite (a mixture of Magnesite/Hematite). This exceptional beauty is named for the gemstones resemblance to the Pinto horses with brown on white patches known to roam free in the Southwest and the favorite horse of many Native Americans. Wild Horse is antique white color with rich chocolate brown matrix, with varying degrees of browns, rusts, olives, and some light pinks. It is not a Turquoise, for it does not have the same mineral composite of Turquoise, but is a mix of Magnesite and Hematite or considered an Ivority/Hematite mixture. This is only mined in Arizona and should not be confused with Wild Horse or Appaloosa Jasper which can be found in California and Oregon.
This rare beauty retains a high value and is becoming remarkably popular in jewelry making. At the Holiday Shopping Extravaganza this weekend in San Antonio, I’ll be premiering this new stone in a design of Wild Horse mixed with Ivoryite, Crystal and gun metal daisy spacers. 
Side note: As a former horsewoman, I know the difference between Pinto and Paint horses. These two breeds look identical in some cases; the difference is in the breeding bloodlines as to whether they are registered as Pinto or Paint horses.
Some excerpts are from Pinto Horse Association website
