Italian Mountain, Colorado

By webmaster at 4:23 pm on July 13, 2008 | No comments

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.

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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.

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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 zhttps://10xminerals.sslpowered.com/blog/wp-content/themes/Gemini-Plus/images/italian-mountain156forweb.jpgones 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.

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

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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.

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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.

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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.

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Heulandite crystals to 3mm from saddle area.

A high-clearance 4WD vehicle is recommended if you intend to approach Italian Mountain from either direction. As with most high-altitude collecting expeditions, remember to take warm clothing and rain gear and be prepared to abandon the heights during the thunder storms that are common in Central Colorado during much of the collecting season. Tools should include at least a small pry bar, small sledge, chisels and a whisk broom. My information is dated, so check access and ownership while planning a trip.
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Paraiba Tourmaline Mine, Brazil, 1988

By webmaster at 3:39 pm on April 9, 2008 | 3 Comments

In the spring of 1988 we spent a month in Brazil. We were looking for the usual mineral and gemstone specimens, and wanted to stock up on quartz and things like spheres for the ‘crystal craze’ that was in high form then. Our primary purpose was more long-range, however. The previous year a friend of ours who lived in Sao Paulo had visited the states and had brought with him several faceted tourmalines from the Paraiba occurance. These were of the best tourquoise color and attracted a lot of attention as the area was little known at the time. He wanted a geological evaluation of the mines so we agreed to follow up and do a field check of the producing area. We all wanted to see if there was any possibility of acquiring either a source or ownership.
Arrangements were made to meet with one of the developers of the property. We traveled to Paraiba state to meet him, flying into Recife on the coast and then to Campina Grande where we met Hector. Hector was a well-to-do man by local standards, a road repair contractor, who had sold most of his business equipment in order to pursue mining the tourmalines at Paraiba. We met him at a hotel in a small town where we looked at bags of stones, mostly small fragments of crystals with mixed quality and color and with none of specimen quality. In the morning Hector took us further into the ‘wilds’ stopping to show us a home he was building for his family. It was very basic by our standards, cement floors and walls, one water source and a bathroom separated from the house. We drove in a small jeep some 25-30 Km, over dirt tracks that would have been impassable in wet weather. At one point he leaned on the horn in the middle of nowhere and we all wondered why. As we crested a small hill, there was a gate across the road and a small boy was pushing it open. Our driver slowed, but never stopped, and handed the boy a bill, maybe 50 cents, that would make his week.

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We arrived at the mines and the small village of Sao Jose da Batalha. It was a typical one street village, with mostly stone or cement homes with red tile roofs and large window openings with no glass or screens. Goats and pigs and a variety of dogs made themselves at home just about everywhere, including inside some of the homes.

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The mines all followed a very clear structure that crossed a hill, probably covering 40-50 acres. From the crest of the hill the structure could be seen in the distance revealed by the white waste rock around pits and trenches in the associated pegmatite. According to Hector, there were more locations for gemstones on the structure, but none had the color of those at the site we were evaluating. On the hill there were large trenches and open cuts, some clearly quite old. These showed areas with wonderfully colored, zoned pink and tourquoise tourmalines in matrix. Fine specimens but not the gem crystals we were looking for. As I recall, there were some very active wasps in the area as well. To compliment the wasps there were some attractive but toxic caterpillars on the bushes. Teri approached one of them and was warned the she would have ‘24 hours of pain’ if she touched it.

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There were two active workings on the hill at that time. One, a vertical shaft, was producing very little. The miners offered me a tour but after looking over the way they maneuvered down the shaft (20 meters deep) with only an old-looking rope attached to a flimsy tripod of sticks and what might have passed for steps in the walls, I declined. Twenty years ago I was much more agile and a lot lighter but still no match for those guys.

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The second workings were more productive and had been open-cut but, following a rock slide, were contained in an adit designed to intercept the pegmatite under the previous surface openings. There was one miner working with very basic hand tools and progressing a few feet a week. Hector wanted enough money to get some drilling equipment and a diesel powered compressor to speed things up. Everyone agreed that the rare crystals of gem quality were “limpia, limpia” and as big as our fingers. Following the tour we retired to Hector’s town home where his mistress (he was a two family man) had prepared rice, beans and some sort of meat. We talked about the problems of obtaining mining rights as ‘outsiders’ and it really came down to trusting a local, Hector in this case, with a lot of money. It is a bit more complicated than that, but it became clear that inspite of the obvious potential, we would have a difficult time gaining a realistic controlling position there. Over the next few years many fine crystals and gem stones were produced from these mines. We never did find out if Hector was able to continue with his operations or if he was part of this success.
We returned to Campina Grande for the evening. After a nice meal and a stroll around the downtown shopping area, occasionally passing open-air coffin vendors with products displayed leaning against the store fronts, and returned to the hotel. We left for Recife and points south in the morning.

Steve Rose

Filed under: Rocks & Minerals, Brazil Tourmaline3 Comments »