Dioptase from Christmas Mine, Arizona, USA

Overview

Christmas Mine dioptase is one of the most distinctive American expressions of the species: not the big, glassy rhombohedra of Tsumeb or the deep-green clusters of Congo, but bright, intensely colored Arizona copper-silicate material from a complex skarn and porphyry-copper system in the Dripping Spring Mountains of Gila County. The best pieces show emerald- to blue-green dioptase as sparkling microcrystals, radiating sprays, hemispheres, “bow-tie” groups, or small balls on pale calcite, chrysocolla, apophyllite-group minerals, cuprite, native copper, or altered skarn matrix. The crystals are usually small, but the contrast can be superb: green dioptase against white calcite, blue chrysocolla, red cuprite, or pale apophyllite is what gives Christmas Mine specimens their particular charm.

The locality matters as much as the mineral. Christmas Mine is a classic Arizona copper locality, a former underground and open-pit operation that produced copper with gold and silver byproducts, and later became famous among systematic collectors for its rare secondary and retrograde silicate assemblages. It is the type locality for several minerals, including apachite, gilalite, junitoite, and ruizite, and it has long had a special reputation among micromounters and collectors of copper silicates. Dioptase fits naturally into that story: it is one of the brilliant secondary copper species that formed where oxidizing fluids worked through fractured, altered carbonate and calc-silicate rocks.

Collectors prize Christmas Mine dioptase for locality character rather than sheer crystal size. A first-rate example does not need large individual crystals; it needs sparkle, coverage, color, and association. The ideal specimen has vivid green, lustrous, well-individualized crystals or radial aggregates, clean contrast with calcite or chrysocolla, and a sound old Arizona provenance. Larger plates with dense microcrystalline coatings can be attractive, but the most satisfying pieces are those that hold up under magnification and reveal sharp crystal form rather than a mere green stain.

Featured Specimens

Locality Information

Search for specimens: View all dioptase specimens from Christmas Mine, Arizona, USA

Christmas Mine lies in the Banner Mining District near the former townsite of Christmas, in Gila County, Arizona, roughly north of Winkelman and south of Globe, near Hayden. The mine is inactive. The principal workings included both underground shafts and later open-pit mining; historical accounts describe five shafts, including a main three-compartment shaft developed to the 908-foot level. The mine has also been referred to historically by associated names such as Red Bird shafts, Inspiration Mine, and Hackberry shafts.

Geologically, Christmas is not a simple oxide-copper pocket locality. It is a skarn-related copper system connected with porphyry-style mineralization. Paleozoic carbonate rocks, including the Martin, Escabrosa, and Naco limestones, are intruded and altered by a quartz diorite to granodiorite porphyry system and overlain by Cretaceous volcanic rocks. Ore-forming fluids moved through limestone contacts, favorable beds, garnetized zones, and fractures. The deposit is described as contact metamorphic or pyrometasomatic in character, with strong skarn development and later hydrothermal and oxidative alteration. That geological complexity explains the locality’s unusual collector mineralogy: garnet, diopside, wollastonite, calcite, apophyllite-group minerals, kinoite, junitoite, gilalite, apachite, ruizite, chrysocolla, cuprite, malachite, and dioptase all belong to different chapters of the mine’s alteration history.

The Christmas story begins with copper discoveries in the late nineteenth century. Early claims by Dennis O’Brien and William Tweed were made in 1880, but the original ground proved to lie within the San Carlos Apache Indian Reservation and the claims were invalidated. After a boundary change restored the ground to the public domain in December 1902, George B. Chittenden relocated the claims on Christmas evening, giving the mine and later town their enduring name. Serious mining began around 1905. The early operation struggled with remoteness, poor roads, and smelting logistics; development improved after a rail spur and the Hayden smelter made treatment of ore more practical.

From 1905 to 1981, the mine produced 25.8 million tons of ore yielding 362.9 million pounds of copper, 55,000 ounces of gold, and 2.15 million ounces of silver. Copper grades varied widely, from low-grade disseminated material to richer ore. Underground mining dominated the early and middle years, but by the 1960s unstable underground conditions pushed the operation toward open-pit methods. Copper mining was suspended in January 1982, during the severe copper-market downturn of that period.

For collectors, most Christmas Mine dioptase represents material recovered historically from mine workings, dumps, or associated oxidized zones rather than newly available field-collected production. The property later passed through major copper-company ownership and is now controlled by Freeport-McMoRan. It should be treated as closed to casual collecting. Modern Christmas Mine dioptase is therefore a market and collection locality, not a public rockhounding destination.

Notable finds span more than dioptase. The mine is the type locality for junitoite, ruizite, apachite, and gilalite, and it is an important American locality for kinoite, stringhamite, whelanite, and other unusual copper-calcium-zinc silicates. Dioptase is one of the more visually accessible Christmas minerals, but its real collector context is this rare, chemically rich, carbonate-hosted copper-silicate environment.

Characteristics of dioptase from Christmas Mine, Arizona, USA

Christmas Mine dioptase is typically small-crystal material. Individual crystals are commonly around the millimeter scale or smaller, though they may form sparkling crusts, radial clusters, bow-tie groups, spherical aggregates, and hemispheres several millimeters across. Dealer and auction descriptions repeatedly emphasize microcrystals, scintillating surfaces, 1 mm crystals, 3 mm balls, 5 mm hemispheres, and vug fillings rather than large freestanding crystals.

The color ranges from emerald green to blue-green and, in some descriptions, pale green. The most attractive pieces show rich saturation and high luster, especially when crystals sit on white or colorless calcite. Some specimens carry dioptase as radiating sprays coating calcite; others show isolated green spherical clusters scattered over a miniature matrix plate. The Christmas habit can look almost “nubby” or acicular under magnification, and specimens often reward inspection with a loupe.

Calcite is the classic contrast mineral. White to colorless calcite rhombs or crusts can make the green dioptase appear brighter, and calcite-rich pieces are among the most displayable Christmas dioptase specimens. Chrysocolla is another common companion, especially as blue-green matrix or copper-silicate masses beneath dioptase. Other documented associations include apophyllite-group minerals, hydroxyapophyllite-(K), fluorapophyllite-(K), cuprite including chalcotrichite, malachite, native copper, kinoite, junitoite, wulfenite, quartz, and chalcanthite. These associations are not incidental; they are the locality’s fingerprint.

The best Christmas Mine dioptase is judged on five things: color, luster, crystal definition, contrast, and locality character. A tiny but sharp, glittering, saturated group on calcite may be more desirable than a larger dull green coating. Pieces with dioptase plus calcite, chrysocolla, native copper, cuprite, or rare Christmas silicates carry added locality interest. A specimen with old collection provenance—especially Arizona collector provenance—can matter significantly, because fresh access is poor and much of the best material now circulates through older collections.

Large cabinet-size examples exist, but many are visually dependent on microcrystal coverage. Small cabinets and miniatures can be excellent if the dioptase is bright and well distributed. Thumbnail pieces can also be important when the crystals are crisp, lustrous, and associated with clean calcite. Under magnification, the difference between true crystallized dioptase and a green copper-silicate film becomes decisive.

Christmas Mine dioptase is a classic locality specimen, but it is not abundant in the way Tsumeb, Mindouli, Kaokoveld, or modern African material can be. It appears periodically from older collections, dealer archives, and estate material, rather than as a steady new supply. Market examples range from modest miniatures with small green crystals to high-quality association pieces with calcite, chrysocolla, cuprite, or native copper. Recent public listings have included inexpensive small miniatures, several-hundred-dollar thumbnail to small-cabinet pieces, and more expensive association specimens when copper, calcite, or strong provenance is involved.

Authenticity concerns are mostly about locality and identification, not elaborate treatment. There is no well-established Christmas Mine-specific fake or treatment category comparable to the notorious problems seen in some dyed or manufactured decorative minerals. The realistic risks are mislabeled Arizona copper specimens, green chrysocolla or malachite sold casually as dioptase, and old collection labels that use abbreviated locality names. A confident Christmas Mine dioptase should show actual crystallized dioptase—ideally sharp, lustrous, trigonal-looking crystals or radial aggregates—not just a green coating. Associated calcite, chrysocolla, apophyllite, cuprite, native copper, kinoite, or skarn matrix can support the attribution, but they do not prove it by themselves.

Condition is important because the crystals are small and exposed. Micro-chipping, bruised aggregate tips, rubbed high points, and calcite bruising are common things to check. Sawed bases are not unusual on matrix specimens and are not inherently a problem if disclosed and if the display face is natural. Calcite associations can be attractive but fragile; avoid acid cleaning unless the mineralogy is fully understood, because calcite and some secondary copper minerals will not tolerate careless treatment. Dioptase itself has good color stability in normal display conditions, but it is brittle and should be handled as a cabinet mineral, not as rough lapidary material.

For buying, the most desirable labels read beyond “Arizona dioptase.” Look for Christmas Mine, Christmas, Banner Mining District, Gila County, Arizona, USA, and pay attention to provenance. Ex-collection notes from recognized Arizona collectors or long-established mineral dealers add confidence. Pieces described only as “Christmas Mine” should still be checked against the actual visual style: small bright green crystals, often with calcite or chrysocolla, are much more plausible than large isolated gem crystals.

Stories & Field Notes

The mine’s name is one of the great place-name stories in Arizona mining. The early claims sat inside the San Carlos Apache Indian Reservation, which made the original locations invalid. George B. Chittenden spent years trying to get the boundary changed, and when the ground was finally restored to the public domain in December 1902, the news reached camp at the perfect dramatic moment. Chittenden and N. H. Mellor moved fast, staking the claims on Christmas morning. Their remembered line—“We filled our stockings and named the place Christmas in honor of the day”—gave the mine a name that no later corporate ownership or open-pit expansion could erase.

The town that grew around the mine carried the joke into American postal folklore. Christmas, Arizona, had a post office that opened in 1905 and then rose and fell with the fortunes of the mine. During the holidays, people around the country mailed cards and packages there just to have them re-mailed with a Christmas postmark. The postmaster’s pay depended heavily on stamp sales, so the Christmas rush mattered. The post office closed for good on March 30, 1935, but the name had become so fixed in the public imagination that holiday mail reportedly kept arriving for years afterward and had to be forwarded through nearby Winkelman.

One of the best collector stories belongs to a cabinet specimen sold as self-collected by Bob Hauck in 1984. The description reads like an old-school field collector’s trophy: “scintillating, gemmy and lustrous” emerald-green dioptase crystals filling several vugs on both sides of a dense ore matrix, with blue-green chrysocolla and malachite as complements. The piece measured 12.1 x 9.8 x 3.6 cm, unusually large for the locality, and was valued at $750–1000 when auctioned in 2011. The cataloguer’s astonishment is telling: “I for one, have never even SEEN a Dioptase from here.” That reaction captures the way Christmas Mine dioptase sat for years slightly outside the mainstream—known to Arizona specialists and micromounters, but still startling when a rich, display-sized example appeared.

More recent public auction descriptions show how collectors have come to recognize the locality’s style. A 2024 small-cabinet dioptase with calcite from the Tom Hales and Alex Neufeld provenance was described as having unusually high luster and complex, scintillating crystals around 1 mm across, interspersed with white to colorless calcite. The cataloguer made the point every Arizona collector understands: African dioptase may be easy enough to buy, but a good Arizona specimen is another matter entirely. A 2025 “bow-tie” group specimen, ex George Loud and Dick and Joyce Willis, brought the Christmas habit into focus again: not giant crystals, but distinctive sprays and groups from a locality whose appeal lies in texture, history, and association.

Mineralogical Records & Publications

Briggs, D.F. (2021), “History of the Christmas Mine, Gila County, Arizona,” Arizona Geological Survey Contributed Report CR-21-A, 45 pp. — The best modern historical overview of the mine, including production figures, ownership, mining methods, and geology.
Arizona Geological Survey, “Christmas Mine of Gila County, AZ — 1880s to 1982” — Concise AZGS summary of the mine’s geology, production, mining history, and closure.
Peterson, N.P. and Swanson, R.W. (1956), “Geology of the Christmas copper mine, Gila County, Arizona,” U.S. Geological Survey Bulletin 1027-H — Foundational USGS economic-geology report based on mine workings and diamond drilling.
Peterson, N.P. and Swanson, R.W. (1956), USGS Bulletin 1027-H PDF — Direct access to the original report.
Ross, C.P. (1925), “Ore deposits of the Saddle Mountain and Banner mining districts, Arizona,” U.S. Geological Survey Bulletin 771 — Early district-scale treatment covering the Banner Mining District context.
Ross, C.P. (1925), USGS Bulletin 771 PDF — Direct PDF of the historic USGS bulletin.
Perry, D.V. (1969), “Skarn genesis at the Christmas Mine, Gila County, Arizona,” Economic Geology, 64(3), 255–270 — Key paper on the skarn origin of the Christmas deposit.
Williams, S.A. (1976), “Junitoite, a new hydrated calcium zinc silicate from Christmas, Arizona,” American Mineralogist, 61, 1255–1258 — Original description of junitoite from Christmas Mine.
Williams, S.A. and Duggan, M. (1977), “Ruizite, a new silicate mineral from Christmas, Arizona,” Mineralogical Magazine, 41, 429–432 — Original description of ruizite from the Christmas Mine assemblage.
Cesbron, F.P. and Williams, S.A. (1980), “Apachite and gilalite, two new copper silicates from Christmas, Arizona,” Mineralogical Magazine, 43, 639–641 — Original description of two rare copper silicates from the Christmas tactites.
Mindat type-locality report for Christmas Mine — Quick reference for the minerals for which Christmas Mine is the type locality.
Mindat dioptase occurrence record for Christmas Mine — Species-specific occurrence page for dioptase at Christmas Mine.
Mindat locality page for Christmas Mine — Broad locality page with coordinates, mineral list, references, and photo database.

“Copper with Dioptase and Calcite — Christmas Mine, Arizona, USA,” EarthWonders — Specimen page with a Vimeo video of a native copper, calcite, and dioptase association from Christmas Mine.
“Cuprite with Calcite, Dioptase,” Weinrich Minerals — Dealer archive page with specimen video for a cabinet-size Christmas Mine cuprite, calcite, and dioptase association.