Willemite and Sphalerite, Miller Canyon, Arizona

Contributed by: Chris Clemens
Date: Apr 18th, 2026
Locality: Nelly James Mine, Miller Canyon, Miller Peak, Cochise County, Arizona, USA (See on Mindat)
Size: 68 x 47 x 75 mm
Weight: 300 g

Description:
This lovely 2-color fluorescent specimen contains willemite and sphalerite and is from the Nelly James Mine (also known as Miller Canyon), in southern Arizona. As shown in the photographs below, the willemite fluoresces bright green under shortwave UV, while the sphalerite shows an orange response under longwave UV. This rock is best viewed under shortwave and longwave UV at the same time to simultaneously see the green fluorescence of the willemite in combination with the orange response of the sphalerite.

Miller Canyon is located in the rugged terrain of the Huachuca Mountains, in Cochise County, Arizona. Near the top of Miller Canyon lies the Nelly James mine. The hike to the Nelly James is 3 miles long and requires a vertical elevation gain of 1500 feet over challenging tread. Being located close to the Mexican border, Miller Canyon provides a route to illegal immigration and drug smuggling into the US, so presents a real possibility of risky encounters on the trail. Despite the risks, the Nelly James Mine has been a productive source of beautiful, multi-colored fluorescent minerals such as this fine example.

The Nelly James was a small open pit lead, copper, zinc, gold and silver mine located in Miller Canyon, in the Huachuca Mountains, Cochise County, Arizona. Its history lasted from the 1880's until 1915 or so. The small amount of ore produced by the Nelly James was inconsistent with the size of the operation, leading to speculation that the property was more of a prospect, and may have been part of a stock scam. The good news for fluorescent mineral collectors is that to this day, the Nelly James Mine has been a productive source of beautiful fluorescent minerals. The specimen featured here was collected in March of 2020 by Ken and Gail Hennig.

Originally posted by Chris Clemens on Nature's Rainbows in 2020.