mining lore – Coconino Lapidary Club

Native Silver – Part I

Mineral Man Mel — Sun, 13 Oct 2024 00:12:47 +0000

This is the first of two Blogs on native silver. In the first I will introduce the mineral, including a gallery of specimens, and in the following blog, “Ancient Silver Jewelry” I’ll present examples of ancient silver jewelry, coinage, and art works, which demonstrate the innovative artisanship of early silversmiths from varied locations around the world.

Among the native elements, silver, [Ref 1], is a favorite among mineral collectors, as it is for me. Silver offers variations in color from metallic silver-white to the optical interference colors of a thin coating film, (such as on copper sulfide minerals – see my earlier Copper Blog), to the sooty black of a thick coating. From locations around the world it occurs in a number of aesthetic and geometrically interesting forms, ranging from groupings of single crystals (Figures 1-2), spectacular fern-like dendritic arrays of crystals (Figures 3 & 4), and striking wire and sheet forms (Figure 5 & 6). The relative arrangement of crystals in, and the shape of, the dendrites has been found to depend on the conditions of the surrounding silver-bearing solution during deposition of the silver, [Ref 2]. Specimens of wires attached to the silver sulfide acanthite, (Ag₂S), grow on oxidation of the sulfide mineral, which liberates the silver, as described below, both by roasting, [Ref 3], or by chemical reactions in solutions within both the oxidized and replacement zones of an ore body, (Slide 9 of [Ref 4]). The wires grow at the interface between the acanthite and silver by continuing the face centered cubic lattice shared by both the acanthite and the silver, [Ref 1]. The sulfur of the acanthite occupies the interstices between the silver atoms. X-Ray diffraction and microscopy have demonstrated the crystallinity of a native silver wire.

In order to share with you these beautiful and intriguing forms of native silver, I’ve included a comprehensive gallery of these forms from around the world, (Figures 3-17). I’ve also taken the liberty of including a favorite specimen from my silver collection in the gallery, (Figure 10).

Because the lore of lost precious metal mines, particularly those in Arizona, New Mexico, and Nevada fascinate many of us; I’ll begin referencing descriptions and histories of these mines and provide brief excerpts from the references. In this blog, the emphasis will be on lost silver mines and in future blogs on silver minerals. Future blogs on Gold and Gold minerals will also include lore & history of lost Gold mines.

Silver Crystal Forms

Silver belongs to the isometric crystal system, [Ref 1], and crystallizes in cubic and octahedral forms as shown in Figures 1 and 2. The forms reflect the symmetry of the isometric crystal system. Silver crystals form twins on the octahedral surfaces of two crystals resulting in a Spinel-Twin, [Ref 6], with the remainders of each of the octahedrons visible, as seen in Figure 3.

Figure 1. Silver crystal in octahedral form, [Ref 1]

Figure 2. Silver crystal in cubic form, [Ref 1]

Figure 3. Twinned silver octahedrons, a Spinel-Twin, [Ref 1, 7]

GALLERY OF NATIVE SILVER SPECIMENS

Figure 4. Cubic crystals of native silver on calcite, Kongsberg silver mining district, Buskerud, Norway.

Figure 5. Dendritic silver comprising an array of branches twinned on octahedral faces (Spinel twins, [Ref 3]), Batopilas, Andre del Rio District, Mun. de Batopilas, Chihuahua, Mexico.

Figure 6. Dendritic silver in quartz, comprising arrays of silver crystals twinned on octahedral faces (Spinel-Twins), Creede District, Mineral County, Colorado.

Figure 7. Dendritic silver on native arsenic. Pohla Mine Group, Freiberg, Saxony, Germany. The dendrites feature growth of branches from cubic faces to give mutually perpendicular orientation with respect to the central branch, instead of from octahedral faces as in Figure 4.

Figure 8. Dendritic silver in calcite, “The Road Runner” Batopilas, Andre del Rio District, Mun. de Batopilas, Chihuahua, Mexico.

Figure 9. Wire silver growing from acanthite, Reyes mine, Gunaajuato, Mexico. Note the close relationship between the base of the rams-horn-shaped silver wire and its host acanthite crystal.

Figure 10. Wire silver growing from acanthite crystals, Linquiu, Shanxi Province, China. Note the intimate contact between the acanthite crystal and the silver wire.

Figure 11. Wire silver, Himmelsfurst Mine, Brand-Erbisdorf, Freiberg District, Saxony, Germany.

Figure 12. Silver wire with acanthite in calcite, Kongsberg silver mining district, Buskerud, Norway.

Figure 13. Native silver crystals with native copper crystals, White Pine Mine, Ontonagon County, Michigan. An interesting association found at this locality.

Figure 14. Distorted cubic silver crystals on copper. Wolverine Mine, Houghton County, Michigan.

Figure 15. Sheet silver, Morenci Mine, Copper Mountain District, Shannon Mountains, Greenlee County, Arizona. The sheet-like form arises from crystallization of small crystals in a closely confined space.

LOST SILVER MINES

The location of the Lost Duppa Silver Mine in Arizona, [Ref 8], lies in the numerous mines and ore deposits of the heavily mineralized Bradshaw Mountains, (Figures 11-16). When discovered, the deposit was a ledge of silver-bearing quartz located in one of the many steep canyons located on the east side, of the northern Bradshaw Mountains. The ore was native silver. After his initial find, Duppa failed to relocate his original path to the deposit and never found it again.

Figure 16. Bradshaw Mountains as viewed from Cow Creek Road, an access road to the mountains, [Ref 9].

Figure 17. The Tip Top Mine, Bradshaw Mountains, [Ref 10].

The Lost Silver Lode of Carbonate Creek, New Mexico, [Ref 11]

The discovery of lode was in the Kingston Mining District, located in the southern region of the Black Range in Southwestern New Mexico. Located within the range are the Chloride, Kingston, and Hermosa Silver Distracts which have been rich producers of the metal. The lost lode lies in the Kingston Silver Mining District shown in [Ref 12], which eventually produced silver amounting to over Six Million in USD. The lost lode was discovered along Carbonate Creek near the town of Kingston as surface float of acanthite (silver sulfide). The weights of pieces of the float ranged up to 250 pounds. Ultimately float yielding over 80,000 ounces was found, but the source of the float was never discovered.

Who Is That Masked Mineral Man?

Mineral Man Mel — Sun, 13 Oct 2024 00:12:46 +0000

I’ve been an avid collector of mineral specimens from around the world since my experience, at the age of 13, of finding a beautiful black tourmaline crystal while on a Boy Scout hiking adventure. We were in the upper limits of the gem mining Pala District in San Diego County, California. I’m now 84 and still greatly enjoying my collection and sharing it with friends. In my blog posts, I want to share with you my joy in collecting these beautiful works of the Earth and hope to interest you in collecting them as well. My great pleasure has evolved from their aesthetics – enjoying the beautiful color and crystal forms of minerals, to learning about their geological histories — where and how they formed, their chemistries and crystal forms in relationship to minerals of similar composition, their mining history, and their frequent influence in geopolitics.

In sharing ideas about these subjects I will, because of space limitations, provide short but meaty encapsulations. I will draw abundantly from resources on the web. To complement my input, I will usually provide links to the subject for your further exploration. In a lighter vein, I plan to frequently include the rich lore of mining and of mining men, of prospectors, and of Lost Gold and Silver Mines and of the historic mines, particularly in the Southwest and Mexico.

To begin, what is a mineral? Drawing from the site, Webmineral, I find a number of definitions cited from scientific literature. To synthesize: “a mineral is a naturally occurring homogeneous solid with regularly ordered crystalline structure and a definite chemical composition. They can be distinguished from one another because of these definite characteristics”. Knowledge of these ideas are powerful tools in identifying a mineral specimen. The mineral’s chemical composition leads directly to its color, internal atomic arrangement, and crystal form. For example, the beautiful Rhocochrosite crystal from the Sweet Home Mine in Colorado, shown above, is manganese carbonate, having the chemical formula MnCaCO₃. Its deep red color is due to its manganese content and its rhombohedral form comes from the internal arrangement of atoms.

Because of the importance of chemical and crystallographic relationships in defining a mineral, I’m providing a link to an introductory course to minerology and crystallography offered by the Open University, a long known and excellent United Kingdom source of quality courses offered, at no cost, to world-wide users. I encourage you to open the link and scan the topics offered, as well as the internal links to tools for accessing a comprehensive body of reference material.

I hope you will share your questions and comments with me, submitting them to our “Ask An Expert” feature.

In my next post, I’ll share with you ideas offered by the most senior of collectors on how to build your own collection. Those ideas will include: collecting one mineral species; collecting many; collecting from one locality; collecting worldwide; where to find bargains and much more.

Until then, have fun learning about minerals and collecting.

Gold III – Lost Gold Mines in the Southwest

Mineral Man Mel — Fri, 07 Dec 2018 01:37:55 +0000

Tales of the discovery and loss of rich gold mines such as The Lost Dutchman in the Superstition Mountains of Arizona and the El Naranjal lost gold mine in the Sierra Mountains of Mexico, as popularized by folklorist, J. Frank Dobie, in “Apache Gold and Yaqui Silver” have fascinated many of us. An extensive list of both lost gold and silver mines of the Southwest , each with extensive and entertaining descriptions of their histories, can be found in “Lost Treasure Tales” on the GeoZone Site [Ref 1].

Perhaps the lost mine tale that most of us are aware of, is that of the Lost Dutchman Mine [Ref 2]. One, of 62, hand drawn maps of its supposed location, made available in Reference 3, is shown in Figure 1 and orients it with respect to the prominent geological landmark, Weavers Needle, shown in Figure 2.

Figure 1. Map of the location of the Lot Dutchman Gold Mine [Ref 3]

Figure 2. Weavers Needle, the landmark for the location of the Lost Dutchman Gold Mine [Ref 2].

Two roots for the of name of the lost El Naranjal Mine have been attributed to its location near a grove of trees with oranges (naranjas) or to the orange color of the gold in its ore [Ref 3]. It is supposedly located at the bottom of canyon (Barranca) beside a river and near an abandoned hacienda.

Among many of the discussions about this mine, Treasurenet suggests that proof of the its existence lies in an old road sign naming the road to the mine in Sinaloa and in records found in Guadalajara, which were found by a British consul, describing production in the millions in the 17^thCentury [Ref 4]. In another posting,

TreasureNet, [Ref 5], suggests its location fits that of an 1800’s lost, and very rich gold mine, in the region of the lost Tayopa silver mine [Ref 6], and in another post [Ref 7] that its location lies in the state of Durango.

Ref 1. http://www.thegeozone.com/treasure/arizona/index.jsp

Ref 2. http://treasure-hunting-information.com/?page_id=2641

Ref 3. https://en.wikipedia.org/wiki/Naranjal_mine

Ref 4. http://www.treasurenet.com/forums/tayopa/36414-el-naranjal.html

Ref 5. http://www.treasurenet.com/forums/tayopa/273860-can-el-naranjal-possibly-found-tayopa-complex.html

Ref 6. http://www.treasurenet.com/forums/tayopa/36414-el-naranjal.html

Ref 7. http://www.treasurenet.com/forums/treasure-legends/487274-update-mine-el-naranjal.html

Native Silver – Part I

Mineral Man Mel — Wed, 15 Aug 2018 18:20:46 +0000