In the mid-1970’s I spent a good deal of time working on projects in Central and Southwestern Colorado. Among several areas of interest in the Gunnison area was an exploration project that incorporated much of the Italian Mountain intrusive complex, an area some 15 miles NE of Gunnison. This is one of the premier mineral collecting spots in the western US, one that has been recognized for the unusually fine specimens found there since it was first described by geologists in the 1870’s.

Later discovery of perhaps the only commercially significant North American deposit of gem-grade lazulite adds considerable interest. It is a place of sublime beauty that is seldom visited by mineral collectors because of it’s remoteness, elevation and lack of access for motorized vehicles.

Italian Mountain complex looking west from Italian Creek drainage

This writing will just introduce the reader to the area and the interesting geology and mineralogy there. There is a variety of literature available concerning the general area and the Italian Mountain complex itself. From the collectors point of view, the best reference is a fine article in The Mineralogical Record by Henry Truebe, (March-April, 1984).

Henry spent some time over a period of several years doing thesis work, mining specimens and evaluating the commercial potential for specimens in the area. He identifies and locates all of the significant species found there.

Italian Mountain is located between the Taylor River and Cement Creek drainages and is best approached from the east from a jeep trail that, starting just north of Taylor Reservoir, follows North Italian Creek to the area of the Star Mine in Star Basin. Several mines in this area produced small amounts of lead, zinc and silver from replacement ore bodies in limestone. The ponds in Star Basin are large enough to produce some fine trout for those interested in fishing. From Star Basin the trail turns south, rounding the east end of the long east-west trending ridge that separates Star Basin on the north from Stewart Basin to the south.

Stewart Basin with South Italian Mountain on left and Central Italian Mountain to right.
Vehicle is near the base of the trail that follows the east ridge to summit area.

American Flag Mountain forms a high North-South trending escarpment east of Stewart Basin. A foot trail from the south side of this ridge provides access from the ridge on the east flank of the main peak to the primary collecting area in a saddle at a contact zone just north of and below the 4,078 meter (13,380 foot) summit.

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Author on east ridge. Note colorful brown alteration of sedimentary rocks near summit and the lighter intrusive quartz monzonite porphry to the right.

Access from the head of Cement Creek follows a trail on the ridge northwest of the North Italian Mountain where the lazulite is found and skirts the peak of North Italian Mountain and approaches the summit of (Central) Italian mountain from the north across a talus slope. This is by far the most difficult access and the trail from the east is recommended. Note that the lazulite deposit is located on patented claims and is off limits to collecting without permission from the owners. Truebe located lazulite in several small occurrences around the main peak of Italian Mountain, but none proved to be of commercial interest.
The three peaks of the Italian Mountain intrusive complex are related to three intrusive ingneous stocks, the youngest of which is about 34 million years old and is usually described as a quartz-monzonite-porphyry (QMP). These rocks intrude Paleozoic sedimentary rocks that intrude limestones, dolomites, shales and quartzite. In these reactive rocks adjacent to the contacts with the QMP main stock and related intrusive dikes are developed skarn zones that contain the primary minerals of interest.

Steeply dipping beds of Leadville Limestone northeast of North Italian Mountain at the head of Cement Creek. The lazulite deposit is below and on a ridge to the left.

Italian Mountain summit from saddle to north. Note sedimentary beds and light-colored intrusive dikes and contact.

Looking north from peak to saddle collecting area. Note digging. Light-colored QMP talus and upper Cement Creek in background.

While there are some 80 mineral species described from the area, the most important and accessible to collectors are found in a relatively small area near the summit of Italian Mountain. These include vesuvianite (idocrase), garnet var. grossular, prenite, clinozoisite, epidote, diopside, chabazite and heulandite. Several pits have been opened on contact zones where these minerals have formed in skarns associated with intrusives and shaley sedimentary rocks of the Beldon formation. My favorite spot is in the saddle north of the main peak. Here the the west slope drops sharply some 500 meters to the Cement Creek valley and to the east is a near vertical drop of some 100 meters to a talus slope above Star Basin.

Ponds in Star Basin from saddle area north of main peak of Italian Mountain

In the 1970’s there were some remnant cables attached to the vertical cliffs below this area. Presumably they were used by some of Truebe’s crew to evaluate the contact zones on the cliff face. There are fine vesuvianite crystals here, up to 5-6 cm, although the best are those up to about 2.5 cm both on matrix and as floaters in collapsed pockets.

Vesuvianite, about 1cm, on grossularite-skarn matrix

Larger crystals, particularly those found near the east edge of the saddle area, tend to be corroded and may show unusual silky, fibrous vesuvianite surfaces. In addition, this is an area where there are gemmy grossularite crystals up to (rarely) 2cm.

Heulandite crystals to 3mm from saddle area.

A nice mineral collecting day trip from the Reno area is to the Nightingale Mining District, an area with many mines and interesting geology, flora and fauna. The area produced mostly tungsten with some by-products but has not been significantly active since the demand for the metal declined after the Korean War. There are a number of major mines with associated ruins as well as hundreds of smaller prospects. As with all such areas, approach any mining area with caution. Do not enter mine openings and remember that not all shafts and pits are fenced.

We approached Nightingale from the southwest from the south end of Pyramid Lake and the town of Nixon. Pyramid Lake is one of the largest and deepest desert lakes in the Great Basin; is is one of the remnants of the huge Lake Lahontan that covered thousands of square miles in northwestern Nevada several thousand years ago. From Nixon a gravel road trends north and east crossing a divide to the basin of Winnemucca (dry) Lake. This lake bed is long and narrow and parallels the Nightingale Mountains on the west. Our goal was the MGL mine, some 7 miles north of the main access road and a mile or two up into the mountains.

The road north passes some spectacular volcanic geology and excellent examples of ancient shorelines with associated tufa mounds. in several areas old beach deposits consist of hard, cemented gravels made up of black eroded igneous rocks that flank the basin in the area.

At the lower end of the canyon where the MGL Mine is located is the cement foundation of the processing plant where tungsten ores were concentrated. The ores were crushed and the heavier minerals containing tungsten were separated and concentrated during several stages of processing as they traveled down through the mill. Concentrates were hauled by truck to a railroad for transport to refining plants outside the area.

The road up the canyon required a bit of careful driving and would not be passable in wet weather. The ore chute or dump is located below the main mining operations. Open cuts in the tungsten bearing rocks can be seen above it. There are several adits (horizontal tunnels) that access the ore zones and allow the ores to be moved down and out to be loaded on trucks for the trip down-canyon to the mill.

The dumps around the ore chute and along the access roads contain many of the minerals that can be found in the open pits and tunnels. The MGL Mine is known for particularly fine specimens of large, brown andradite garnets as well as clinozoisite. Some of the best examples can be etched from calcite that fills some veins and pockets, protecting the crystals. Other minerals include pyrite, quartz, tremolite, copper secondary minerals and rare molybdenite.

Although the area is dry this time of year there are a variety of flowers and lots of lizards. Desert plume, Stanleya pinnata, is one of the more spectacular. Lizards like the black-collared, the western whiptail and the sagebrush lizard abound. It must have been a productive spring for them, because there were little lizards everywhere. It is amusing to see a 3-inch lizard on a 6-inch rock, protecting his territory with all of his bravado. The bigger lizards get to protect bigger rocks, and even graduate to a boulder if they are really assertive. And they run like the wind! Even the littlest ones will raise a small plume of dust as they dash down the road.

Returning to the main access road we again went northeast over a pass of about 6,000 feet in elevation to the site of the Nightingale Mines. Here are cement foundations and a metal stack and a large water tank that provided water for the milling operation. Most of the metal structures have been riddled by bullet holes and there is considerable trash left by campers. I have never thought of a water tank as a challenging target, but it must be.

The mining here was concentrated in a steeply-dipping sedimentary unit some 15 to 20 feet thick that has been metamorphosed by nearby and included granitic intrusives. The mining covers some half-mile of strike and has left large, open cuts and overhangs. Dumps contain a similar assortment of minerals as seen at the MGL Mine, but the rock is ‘tighter’ with less opportunity for good specimens where we checked.

Returning over Nightingale Pass we stopped at some smaller workings known as the Jay Bird Mine but found nothing of interest. The rest of the trip was uneventful. Pyramid Lake was calm and some the local white pelicans were having a meeting on the beach as we passed by. All in all a very good day.

In the mid-1970’s I spent some time working in SW Colorado in the La Plata Mountains near Durango. This area has produced significant gold (the Bessie G mine, for example, was active at that time) and has been investigated for its porphyry copper potential and uranium as well.

The Tomahawk Mine and basin are located above timberline in the western part of the complex. Rocks in the area include a variety of intrusives and metamorphosed sediments that form the high ridges and cliffs around the head of Tomahawk Creek. The Tomahawk mine produced gold in the last century. At the time I worked in the area there was still a very thin, rich vein containing visible gold accessible (if you were a skilled rock climber) on the cliff face at the creek near the mine ruins.

Above: Tomahawk Basin seen from high ridge to SE.

Below: Tomahawk Mine structures in 1975.

What passed for a road ended a few hundred yards west of the mine at a drill site located near a small intrusive complex. Talus from the high cliffs to the south of this intrusive contained scattered vugs that were mineralized with epidote, quartz, K-feldspar and rare fluorite. The fluorite crystals were simple octahedrons of a rich violet color. Their maximum size was about 2 mm.

I have always thought that it would be worthwhile to investigate the area for the source of the fluorite. Perhaps there are larger cavities and better crystals in the larger talus or lower cliff faces a few hundred feet up and to the south of the intrusive. Are there any of you energetic young collectors interested?

During our trip to Brazil in 1988 we visited Belo Horizonte, a perpetual hub for the gem and mineral trade in Minas Gerais. We saw a number of dealers with wonderful specimens but perhaps the most memorable was a non-descript office and showroom where we saw the most unexpected and amazing group of beryls. Apparently, these crystals had been found a short time before during road construction and had ended up in the hands of this dealer. Unfortunately, I do not recall his name.

The six crystals weighed a total of 27 kilos; all were nicely terminated and very gemmy and of good color. In the picture they sit on their terminations. The golden beryl was said to be from the same find, but is was not clear if it was actually from the exact same site as the aquamarine crystals. Asking price: $1,000,000.00. We have always wondered where these crystals ended up.