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Mineral Collecting in Mexico By Walter Bowser A safari to Mexico's best collecting areas
Starting in the north at the border town of Ojinaga, Chihuahua we cross into the fertile valley of the Rio Bravo (Rio Grande) and soon begin our climb into the starkly beautiful and strongly folded mountains that lie between us and our destination of Chihuahua. We have a chance for some lessons in geology and to collect our first specimens at the Pequis overlook. This is a fantastic view of some very deep entrenched meanders. The lower part of the canyon is part of an impoundment to provide water for the valley. Farther on we come to some small towns and will venture off the road to see if we can gather some nice wulfenite and vanadinite crystals at the mine or in the town. Chihuahua, Durango, Zacatecas, San Luis Potosi, and Coahuila are all states that we will be visiting. Each state has its own high point.
ChihuahuaChihuahua has Santa Eulalia, Naica and Parral. These famous mining camps are full of color and surprises for the serious visitor. The casual visitor will miss the invitations into the homes to look at minerals which are for sale.
Santa EulaliaThe pueblos of Aquiles Serdan and Francisco Portillos form the West Camp and the pueblo of San Francisco el Grande forms the eastern camp. Here it is possible to visit the mina Bustillos and the mina Coronel. These are a just a short hike from the road. Further and much more interesting is the Mina Viejo. The entrance to the mine is through a natural cave. This is the oldest mine in the district. The minerals in the Santa Eulalia district are limestone hosted hydrothermal vein systems. The super heated waters from down in the magma below the mines brought up highly acidic solutions which ate away the surfaces along the cracks made by the uplift prior to emplacement.The minerals mined here are copper, lead, zinc and a little silver. The rocks are often rich in manganese and iron, hence, we have mangano-calcite, iron pyrite, galena, hemimorphite, smithsonite, goethite, rhodochrosite, ludlamite, vivianite, aragonite, calcite, and many, many more. We have good collecting experiences in Santa Eulalia. Santa Eulalia also has a great restaurant which we can have opened for us. The food is unique and very, very good.
Naica and the Cave of SwordsNaica is the home of the Peoles mine and the Cave of Swords. This famous geologic wonder is located deep underground. There, along the Naica Fault, a medium sized cave evolved. This cave filled with solutions charged with Calcium Sulfate. As the solutions became saturated the crystals seemed to form. The largest formed near the bottom of the cave. There were perhaps several periods of forming and reforming of crystals. Some of the crystals grew to be 3 meters long. The walls, ceilings, and floor of the cave are covered with crystals of selenite so dense at times that they look like cord-wood stacked on the walls. You can be visit the Cave of swords if you have special permission. In the town it is possible to buy materials from the miners but it is good to beware of the vigilantes. These are the guards of the mines who come out and watch you while you are in town. It is difficult to visit a miner's home knowing he might be fired for dealing in minerals. The mining companies often have a no mineral policy to keep the workers from taking minerals when they should be working.
Parral and the Fire Agate MinesHidalgo del Parral, Chihuahua is the site of the fire agate mines as well as the famous mines at Santa Barbara and San Francisco del Oro. Near the town of Parral, which is the site of the assassination of Pancho Villa and his original grave, is a large area covered with chalcedony roses. Just above the field of roses is the fire agate site. We have gathered over 20 pounds of a good grade of fire agate in a little over 2 hour. This material polishes out with a good color ranging from gold/green to purple.
Santa BarbaraIn the near by town of Santa Barbara it is still possible to find nice specimens in the walls of the glory hole at the mina de Agua. The mines at Santa Barbara still produce copper, silver and zinc. A small amount of lead and some gold are produced but are negligible in the over all amounts.The old glory hole is convenient to a street in the town, Santa Barbara is the oldest town in Chihuahua, and produces some nice specimens. You may select a spot that has a spot of malachite or azurite. You may want to pound on the walls to hear a bit of a hollow sound. These are likely to yield some nice specimens of materials such as a fleck of gold, some crystals of quartz covered with azurite or malachite. The gold here is sparse, but it is here. I have some specimens which are loaded with gold which have come from here. One piece has over 20 grams of gold in it. It is also possible that we may see the gambusinos working a vein which the company had not mined. This dangerous practice is accomplished by pick and shovel work, with the miners working high on the walls and deep into a pit. The potential for accident or injury here are fantastic with the way they work. The gold bearing rock is pounded into a powder and either "panned", actually horned, or ground further and mixed with mercury. The resulting amalgam is then heated to remove the mercury, a rather dangerous practice as done here using a frying pan.
DurangoDurango has two great stops for us, Mapimi and Cerro Del Mercado. We also make some road cut stops to collect. Mapimi is world famous for its suite of minerals. Cerro del Mercado has great apatite crystals and great associations.
MapimiFirst stop is in the town of Mapimi. The town is not what it used to be, when the mine was running full blast. It was nonstop minerals sellers around the town square. Now the sellers and miners have to be hunted down. I have my connections here and every now and then find some one new. In Mapimi we find some great adamite, cerrusite, nice hemimorphite clusters and sprays, Wulfenite and cupro-adamite and cobalto-adamite. There are also nice fluorites which come from near here.
Mina OjuelaThe Mina Ojuela, up on the mountain above the town, is really not one mine but a group of mines with over 500 mile of tunnels running through the mountain. The road up the mountain is a work of art. The cobble stones are really well laid and not rough at all. Once on top the Puente Colgante or suspension bridge is found. The bridge was built over 100 years ago and is still used every day. It was built by Roebling & Co., the same who built the Brooklyn Bridge. It is an amazing sight. The wooden towers have been replaced with steel replicas. The bridge had a donkey engine, which ran across it to take ore out of the mine.The dumps here yield some nice thumbnails, good micros and sometimes a nice cabinet. The micros are really the fantastic suite here. I am not a micro collector but I can appreciate the delicate crystals which have been blasted from the earth and lain on a dump for over 50 years or more and survived. I can also appreciate the beauty of the microscopic materials. We spend a day here in the dumps and across the bridge in the mine itself. It is a wonderful experience. On the way from Gomez Palacio to Durango we will stop at a couple of road cuts to view some veins of calcite and other materials which may be dug. The dogtooth calcite is very sharp and I have actually cut my thumb handling one piece.
Cerro del MercadoDurango and the Cerro del Mercado are the next stops on our trek. The Cerro del Mercado is a small resurgent dome which rose inside of the ancient caldera in which Durango is located. This area is affected by the zone's interior drainage system which deposits great quantities of water on the floor of the caldera in some wet years. This leads to local flooding and road closures. Usually though it is not that bad.The ancient volcano blew its top millions of years ago. The resurgence many years later pushed up two domes in the valley of the caldera. Cerro del Mercado was almost pure iron ore. Cerro del Remedio was laced with tin. The tin mines are closed and not accessable. The mine at Cerro del Mercado is a producing mine, which opened up in 1995 after 8 years closure. Here you will find beautiful apatite crystals. I have seen some which are facetable, but most are specimen pieces. Partly the method of blasting and the uplift caused them to be fractured internally. The associations here are apatite with martite, opal, chalcedony, asbestos and hematite. The apatites run from pencil lead size to as large as the last joint of your thumb. The deep yellow color is beautiful and fiery when faceted. This is quite a stop. It is not easy to enter the mine and if we didn't know the mine engineers and manager we would not be able to enter. They are very strict about entrance and digging here.
ZacatecasZacatecas will have stops at San Martin, Fresnillo, San Nicholas Veta Grande, and Pinos. We will visit a mine, mining camp and perhaps go to the mine at a depth of over 1600 feet. We will also be able to find native silver sheets and stibnite as well as some very gemmy calcites.
San MartinSan Martin (Sahn Marteen) is a small village off the main road. The only thing that lets one know that there is anything here is the sign at the main highway turn off. However, if one looks really hard there are giant buildings which blend into the land scape high up on the mountainside. These are the mine mill buildings. If you stand at the cutoff and listen you can here the whine of the giant turbines which power the air conditioning and ventilation units for the mine. Here we will encounter sheets of pure silver. This is material that is too rich for the mill. It is so soft that if pounds into large chunks and mats which inhibit the ability of the ball mills to crush the rock into fine enough particles for processing.The silver here is covered with a shiny blue coating of bornite. It does not look much like silver but is very pure and very ductile. I have been lucky enough to get some sheets of silver which have been over 24 cm long by 15 cm wide. Great amounts of silver come from this mine. The mine also produces beautiful gemmy calcites and fantastic stibnites. It is amazing to me that you can get this material out of the mine in one piece. I have in my collection one piece which is 18 cm long and about 6 cm wide. The crystals are all nicely arrayed and very shiny. The stibnite is also found associated with beautiful calcite. This is some of the gemmiest calcite I have ever seen. Nice pyrite cubes up to 3 cm have been found here too.
FresnilloFresnillo will produce some nice pyrargarite crystals, polybasite, argentite, chlorargerite, and sometimes native silver. This town is not the most open town around. Some of the sellers of minerals from the mine have been hassled by the vigilantes. We have been in the mine and received warmly. However this is not a town to be treated lightly as far as the vigilantes are concerned. Be cautious. One of my friends spent time in the local jail for selling "changitos", little silver specimens. It is not too bad if you are careful. But, I no longer go to his house to buy. Instead, we go to the motel and he brings me the materials. I have some beautiful pyrargarite crystals from here which are translucent and red. I have also, two specimens of silver wire. over 1 and a half inches long. This is a fabulously rich mine and many wonderful specimens come from here. I have seen some that I could not afford but drooled all over because they were so beautiful.
Veta GrandeNear La Bufa in Zacatecas is located Veta Grande. This sleepy town has the most unique church in Mexico. it is a Nordic style with rounded domes which look like nothing in the area. It shows nothing of the Moorish style. Here we can enter the mine and descend to the working areas and pick samples off the walls. We have free reign of the area. Our hosts here are the mine owners who are delighted to see you and take time to let you enter their mine and PLAY awhile. They are most hospitable and gracious. On our first visit to the mine he sent someone to the working face to bring back some material. The miner brought back a chunk of ore which weighed about 100 pounds. Then he proceeded to break it apart with a sledge hammer to give pieces to us. Down in the mine it is a bit muddy in places but surprisingly cool because of the ventilation. Back in the closed in working face it is steamy and very warm. We have access to the working face and can take as much as we like of this very rich silver ore. Here the silver is found in galena and as free silver sulfides or native silver. The native silver is rare, however. The silver sulfides are often small blobs in the rock or rarely crystals in vugs. More often there is a reddish smear on the broken face of the rock indicating pyrargarite. There is also in this mine an unidentified silver/lead sulfide. Going down in the elevator is quite an experience. The single steel cable tends to stretch a bit as you go up and there is about a 10 foot yo-yo effect from time to time. It is not noticeable as the stretch is pulled taut on the way down. Going up, after a few hundred feet, there is a noticeable stretch to the cable. This is quite a thrill. I think there is very little danger, but is still a bit of a scare when it happens. On to Panfilo Natera.
Panfilo NateraIn Panfilo Natera we will stop to see if there is anyone with any material from the Tesora Blanca mine located a few miles away. It is an area we are just trying to open up. It is a producer of some spectacular yellow calcite and aragonite groups. Who knows what will be produced here today?
El Salvador MineA few miles further on there is the mina El Salvador. This mine is an old Spanish copper mine which a friend of mine has reopened a few years ago. The mine is down several hundred feet. The mine produces some nice azurite and malachite crystals as well as massive materials. There is also some gem silica, chrysacholla, found here. We can dig on the piles waiting for treatment or go over to the open pit portion and collect from the rock face. Here, also, is found some bright yellow cadmium salt. We are not sure which one it is but it is quite bright and pretty.
PinosPinos is a fairly large town with a history of mining. The mines are all shut now but with better techniques and more efficient treatments the mines are going to open up again. The Canadians are opening a large mine here in the areas of the old mines. Their goal is to mine the less rich ores which the Spanish, French and Americans left behind. It is the improved methods, and the economy of large scale operations which make this possible. I was talking with a Canadian geologist who showed me a rock about double fist size laced with gold stringers. There was almost 1800 grams of gold in this rock. I stated that this probably made the whole thing worth while. His comment sort of staggered me until I thought about it. He said, "it is the stuff around it which makes it worth while to mine this stuff." There is not enough of this rich ore to warrant the mining of it in a full scale operation. However, in a large scale mine this is just icing on the cake. We will stop briefly here to see if there is anything produced which we might be interested in. This is also an area rich in Indian artifacts. Do not get caught with any of the idols or statues.
San Luis PotosiSan Luis Potosi will see us stopping for topaz in Tepate and then for Danburites and other associated minerals in Charcas. We will enter Real De Catorce through a 2 KM long tunnel and will be able to find some really nice stibiconites.
TepateTepate is a wide spot in the road. One of the ways to know that you are coming to the village is that you see a sign which looks like it has two military style helmets on it. LOOK OUT! Topes ahead. These are anything from a pile of asphalt about 1 foot high across the road, usually in 2s or 3s to the metal "helmets" across the road in several rows. This a good place to break an axle. At best if you go too fast over the topes or vibradoras you will be shaken well. In Tepatate we can visit with several miners and arrange to come back after the regular trip to dig some topaz from the "mine." This is actually a large trench or a cliff face of rhyolite in which the topaz are found. If you wish to come back the miners will take you out for about 20 dollars a day as guides per person. On this brief stop today we will see several hundred kilos of very good to junk topaz. Nothing is thrown away by the miners. I bought 40 kilos of junk to give away to kids and others at a show. it was very cheap and the topaz was a hit. One kid even found a really nice one in there.The trip down from the highlands to San Luis Potosi is spectacular at the very least. We have about 30 miles of really curvy, winding road which hugs the cliff face over looking a beautiful canyon. The road passes a reservoir and several villages. The hills here are made of some very pink rhyolite which is called here, Cantera. This rather soft stone is carved by the artisans in the villages along the way. Some of the carvings are elaborate and large. Pillars, statues of gods and goddesses, gargoyles, lions, animals of all sort and custom orders can be had here very inexpensively compared to the U.S.
GuadalcazarThe next morning we leave San Luis Potosi for Guadalcazar. This is a hidden gem of a village located only 30 Km off the main highway from Saltillo to San Luis Potosi. This village was a booming mining town just one hundred years ago. Now it is the commercial center for a very small farming area. Near by are mines for limestone to produce cement, and marble for tiles, and fluorite and gold mines which are abandoned. From the fluorite mines we get some of the most beautiful facet grade fluorite. This material looks like ice in the rough. It is colored purple, lavender, peach, blue, green, and a pink-peach. We are only able to get pieces from 1 to 2 inches across but have the promise of more. The gentleman who has the concession on the mine also mines some colored marbles and slates for flooring materials. The material which he has is beautiful.A little story about his wife. The first trip into the town we know no one. I hunted around and finally located the place I had been told had stones. I spoke in my poor grade of Spanish and made myself understood. She sent the kids to fetch papa and conversed with us in Spanish. Finally I got stuck for some words and she said in fluent, Texas accented, English, "You speak well but you need more practice." I was floored. She had grown up in Texas and moved back to the village to marry her sweetheart. It was a touching story and she is a lovely person. The family is struggling but with the resourcefulness of the father and mother they will make it.
CharcasLeaving Guadalcazar we will go on to Charcas to find the elusive danburites. About an hour after we leave the village we arrive in Charcas. We go to the mine first and visit with friends in administration then go to the mine ramp and down about two thousand feet to the danburite locality. Perhaps there is good material here today or perhaps not. One never knows. It is interesting to enter the mine with the smell of exploded dynamite still on the air. We go down the ramp deep into the earth, through intersections with other ramps and tunnels, past powder magazines, work shops, repair facilities and into an area that suddenly becomes more quiet and cooler than the part of the mine we came through. Looking ahead we see the headlights of the tractor are lost in the blackness of the mine. Looking up we see nothing. We are in a stope which would hold the great cathedral at Zacatecas. The ceiling arches upward into the darkness and the only thing we can see is the giant pillars which support the top of the mine. 2000 feet of rock above us supported by massive pillars. Listening, off in the distance we hear the plaintive clunk, clunk, clunk, of a pump draining a sump, trying to keep up with the water dripping in to the mine from above. We leave the tractor and wander to the walls looking for the glint of crystal faces in the rock. When we find a hollow spot we get out the hammers and break apart the living rock to hunt down what is in the vug. This time it is calcite, or danburite or some other crystal. Who knows what the next will be? For a couple of hours we are here in the mine and then go topside to go into town for the next phase of the stay here.The town is full of people who have minerals. The minerals include danburite in pink and clear clusters to 8 inches across. I did get from the mine one time two clusters which weighed over 70 kgs each. That was a find. We will find blue stalactites from a mine near here. These are constantly being replaced because of the drip of copper carbonate charged water into the mine. Fluorite, fantastic calcite clusters, and shapes of calcite are often found here. The danburite sometimes is mixed with crystals of datolite. Many minerals are found here and are quite spectacular in their forms. Even the common calcite has grown into forms which I have never seen before. I have three pieces in which the calcite has grown in shapes which others have stated is so unusual that I should give them to a museum.
CatorceWe usually have dinner with friends from the mine and then carefully go to Matehuala for the night. After breakfast in the morning we will go to Catorce about an hour away. The town sets on the other side of the mountain from us and is entered by a 2+ KM tunnel. This is the only vehicle entrance to town. Here we can find nice stibiconite pseudomorphs after stibnite for sale. The town is a tourist mecca in certain months of the year and sometimes presents a problem to enter because of all of the people making pilgrimages to the shrine here. The church here is famous throughout Mexico and people make great cross country pilgrimages here. The floor of the church covers the coffins of the faithful who are buried here. They lie just under the floor. The floor boards buckle and wobble as you walk along. The altar in the church is brilliant with the gold and gilt trappings. Lighted candles glimmer in the sides of the altar, the faithful few kneel and prey, tourists gawk and fill the air with flashes from cameras. After leaving Catorce we drive through a forest of Joshua trees and arrive in Concepcion del Oro. The mine here does not produce much gold. In fact it produces little at all now, because it has been in financial trouble for about 5 years. Still there is a 26 person maintenance crew here to keep it from flooding and going into ruin. From these men we can glean specimens which are quite beautiful. A suite of copper minerals including brochanthite, malachite, fantastic azurite crystals, and many more. Also from here comes some of the best cubic pyrite clusters in Mexico. The pyrite here is beautifully brilliant and comes in large cubes of up to 2 inches on edge. Most is smaller but I have seen clusters of 2 inch cubes on many occasions.
CoahuilaWe wind the trip up with a final dinner in Saltillo, the capital of Coahuila. This town is a very cosmopolitan town with a large international student population. It is a comfortable town with lots of parks and green belts. I like the area nearby because there are mountains with many valleys an streams with forests of pines and oaks. It is cool and comfortable in the mountains all year long.
Stay in nice motels and enjoy great food, great company, and great minerals. We have FUN and enjoy the trips like each time was the first time. The trip of a life time for the memories of a life time.
Permission is given to freely reprint this article from the Canadian Rockhound for non-commercial and educational purposes, provided the author and the Canadian Rockhound are acknowledged, and that the website URL address of the Canadian Rockhound is given. The article may not be edited or rewritten to change its meaning or substance without the author's permission. To contact the author, please use the e-mail or postal address provided. Courtesy copies of newsletters using this article are requested for the author.
Walter S. Bowser
 
Copyright © 1997 Canadian Rockhound
Images of minerals are Copyright ©1997
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