Kelly Mine
The Kelly mine, Magdalena district, Socorro County, New Mexico: zinc and lead from 1878 to 1957, Kelly Blue smithsonite, and 4 of 176 Handbook sheets naming it.
The Kelly mine, Magdalena district, Socorro County, New Mexico, is the source of the smithsonite colour the New Mexico Bureau of Geology calls Kelly Blue (ZnCO3, hardness 4 to 4.5). The Kelly mine produced zinc and lead from 1878 to 1957 (USGS MRDS); 4 of this site's 176 Handbook sheets name the Kelly mine.
In short
- The USGS record. MRDS 10012336 lists the Kelly mine as a past producer of zinc and lead, with copper, silver and gold secondary. Discovery and first production are given as 1878 and last production as 1957. The workings are ten levels reached by three shafts and a tunnel, in the Kelly Limestone along the Kelly–Graphic fault zone. The district record calls it the largest producer in the district.
- Zinc came late. The New Mexico Bureau of Geology gives 1866 for the discovery of ore in the district. Lead and some silver came first, copper became important around 1900, and smithsonite was recognised and worked around 1903. Zinc was the most important metal after that.
- 4 of 176. Four Handbook of Mineralogy sheets in this site’s reference set name the Kelly mine in their Distribution field. Smithsonite says fine examples; rosasite names the Kelly mine; aurichalcite and azurite say the Kelly and Graphic mines.
- “Magdalena” alone is not enough on a label. Two more sheets in the set, howlite and wulfenite, name a Magdalena. That one is Magdalena, Sonora, Mexico. A label that says only “Magdalena” is ambiguous.
- Worked zinc content: smithsonite, ZnCO3, is 52.14% Zn by mass, against 54.29% for hemimorphite, Zn4Si2O7(OH)2·H2O. The smithsonite sheet gives H 4–4.5 and D 4.43. It records that the mineral may fluoresce pale green or pale blue under UV.
| Species | Formula (Handbook) | Hardness | Density | Colour (sheet) | Distribution wording |
|---|---|---|---|---|---|
| Smithsonite | ZnCO3 | 4–4.5 | 4.43 | White, grey, brown; more rarely pale red, pink, orange, yellow, green, apple-green, emerald-green, blue, bluish grey | “fine examples from the Kelly mine, Magdalena, Socorro Co., New Mexico” |
| Rosasite | (Cu,Zn)2(CO3)(OH)2 | 4.5 | 4.0–4.2 | Green, bluish green, sky-blue | “from the Kelly mine, Magdalena, Socorro Co., New Mexico” |
| Aurichalcite | (Zn,Cu)5(CO3)2(OH)6 | 1–2 | 3.96 | Pale green, greenish blue, sky-blue | “at the Kelly and Graphic mines, Magdalena, Socorro Co., New Mexico” |
| Azurite | Cu3(CO3)2(OH)2 | 3.5–4 | 3.773 | Azure-blue, Berlin blue, very dark to pale blue | “at the Kelly and Graphic mines, Magdalena, Socorro Co., New Mexico” |
| Wulfenite (not Kelly) | PbMoO4 | — | — | — | “San Francisco mine, Cerro Prieta, Magdalena, Sonora”, Mexico |
| Howlite (not Kelly) | — | — | — | — | “From Magdalena, Sonora, Mexico” |
Where the Kelly mine is, and what the USGS record says
Position. USGS MRDS record 10012336 puts the Kelly mine about 18 miles (29 km) N 83° W of Socorro, at 2,332 m. The coordinates are those of the Tri Bullion shaft; the Paschal and Traylor shafts and the Kelly tunnel are listed as other names. The district record (MRDS 60000901) lists Kelly, Magdalena-Kelly and Magdalena Mountains among the district’s alternate names.
Geology. The host is the Kelly Limestone and Magdalena Group, with monzonite, granite, rhyolite, latite and andesite associated. Ore bodies are pods and shoots, formed where mineralized solutions rose along fractures and replaced favorable host rock. The record lists smithsonite, sphalerite, galena, anglesite, chalcopyrite, malachite and chalcanthite among the ore materials, with barite, calcite, quartz, siderite and specularite as gangue. That is an ore list, not a specimen list. The district record classes it as a polymetallic replacement deposit.
Ownership in the record. It names New Jersey Zinc Co. (Empire Zinc Division) as owner and J. D. Torres and C. Barrett as operator, both with 1957 as the first year. The record does not say what came after, and we do not state whether anyone may collect there. Other localities are on the localities index.
Which minerals the Handbook places at the Kelly mine
The count is 4 of 176. Method: a script reads the Distribution field (from Distribution: to the next Name:) of each of the 176 sheets in this site’s reference set as pdftotext -layout text, strips diacritics, expands ligatures, joins line breaks and matches case-insensitively. The pattern Kelly mine or Kelly and Graphic mines matches aurichalcite, azurite, rosasite and smithsonite, and nothing else. A broader search for Magdalena adds howlite and wulfenite, both Magdalena, Sonora, Mexico. Those are excluded.
Graphic is a separate mine. Aurichalcite and azurite are listed for “the Kelly and Graphic mines”, so the sheets do not tie those two to the Kelly alone. One sheet outside the set, serpierite, names the Linchburg mine, nine km south of Magdalena, in the same county. It is a comparator and is not counted.
What the four have in common: all are secondary carbonates of zinc, copper or both, from the oxidised zone; see what is a gossan. Rosasite and aurichalcite carry both metals. Aurichalcite is the soft one at H 1–2, recorded as Fragile. The species index has all four species pages.
1866, 1878, 1903, 1957: when zinc took over
- 1866: ore discovered in the Magdalena district (NM Bureau of Geology; MRDS district record, which credits Col. J. Hutchison).
- 1878: discovery and first production at the Kelly mine (MRDS 10012336).
- Around 1900: copper becomes important in the district (NM Bureau of Geology).
- Around 1903: zinc carbonate ore, smithsonite, recognised and worked. Zinc is the district’s most important metal from then on. Complex sulfide ores became the staple after 1908 (NM Bureau of Geology).
- 1957: last production at the Kelly mine (MRDS 10012336).
- 1968: last production in the district (MRDS 60000901). The Bureau’s page says mining continued into the 1960s and the Kelly headframe still stands.
What the dates do not say. Smithsonite was worked here as zinc ore. No source we fetched says when the collector specimens were recovered, so this page gives no date range for them.
Reading a Kelly smithsonite label
The colour name. The New Mexico Bureau of Geology calls the most famous colour of the mine’s smithsonite Kelly Blue. The Handbook smithsonite sheet lists blue, bluish grey, green, apple-green and emerald-green among the species’ colours, but it does not tie a colour to a locality. No source we fetched says what causes the Kelly colour, so this page does not say.
Smithsonite or hemimorphite? Both are zinc minerals of the oxidised zone and both can be blue. Smithsonite is H 4–4.5 and D 4.43; hemimorphite is H 4.5–5 and D 3.475. The full comparison is on smithsonite vs hemimorphite, and the UV question on is smithsonite UV reactive.
A complete label reads Kelly mine, Magdalena district, Socorro County, New Mexico, USA. “Magdalena” on its own could be Sonora. “Kelly and Graphic” is a two-mine attribution. Nothing here is offered for sale; the wanted list is the only commercial route.