(2 troy oz.)
Telluride Gold Ore
(This rich gold ore has microscopic gold, not visible gold.)
_______________________________

Here is a rather rare and special type of
GOLD ORE
that would be a very interesting addition
to a gold-lover's collection.

It is called Telluride Gold or
the Mineral Calaverite.

_______________________________

The sample of Telluride Gold Ore
in this auction weighs
(2 troy oz.).

How much gold is there in Telluride Ore?  "Calaverite (Au,Ag)Te2 : typically about 40 per cent gold."  (This rich gold ore has microscopic gold, not visible gold.)

The following is what a mineralogist would tell us about Telluride Gold Ore, and gold ore minerals in general:

Gold Ore Minerals:
          The most prominent GOLD is native gold.  Most native gold contains a small amount of silver, copper, platinum, etc.
          Telluride minerals are the most common minerals which contain significant gold in their make up. They include: Calaverite (Au,Ag)Te2 : typically about 40 per cent gold; Petzite (Ag,Au) 2,Te, with a gold content of about 25 per cent; Hessite (Ag2Te), with gold often present replacing a part of the silver; Sylvanite (Au,Ag)Te2 : typically about 25 per cent. gold;  Krennerite (Ag2Te,Au2Te3) : gold is about 35 percent; and Nagyagite (Au2,Pbi4,Sb3,Te7,S7). Some samples of Nagyagite have given upon analysis 12.75 per cent gold. The gold containing sulphides, as well as the tellurides, are of primary formation, although auriferous chalcopyrite might also be formed by secondary enrichment processes. Native gold may occur in the primary, secondary enrichment, or oxidized zones. The tellurides, which are usually associated with pyrite, are widely distributed, though not so abundant, but not always recognized; indeed by some miners they are mistaken for sulfides.

THE MINERAL CALAVERITE

• Chemistry: AuTe2, Gold Telluride.
• Class: Sulfides
• Subclass: Tellurides
• Uses: An ore of gold and tellurium and as mineral specimens.

Calaverite is an uncommon and much sought after mineral by mineral collectors. Calaverite is one of the few minerals, besides native gold itself, that is an ore of gold.  It is the most common gold bearing mineral besides native gold. The element gold is typically either found as native gold (in its elemental state), as an alloy with other metals such as silver and copper and as trace amounts in a few minerals. To be an actual significant part of a non-alloyed mineral is really quite uncommon for gold and this makes Calaverite a unique mineral indeed.

For some reason gold has an affinity for the element tellurium, which is sometimes found naturally as native tellurium. Tellurium is a semi-metallic element which means that it has some properties of metals but not all or as strongly. This helps provide an explanation for gold's, and other metals such as silver's, attraction to tellurium. Other gold tellurides include sylvanite, (Silver Gold Telluride); kostovite, (Copper Gold Telluride); krennerite, (Silver Gold Telluride); nagyagite, (Gold Lead Antimony Iron Telluride Sulfide) and petzite (Silver Gold Telluride). Calaverite is closely related to sylvanite and differs only in silver content and slightly in hardness, cleavage, color and density. At times the two minerals are only distinguishable with chemical tests.

Crystals of calaverite are unique and of interest to collectors. Typically found as striated prisms that can be twinned causing sharp bends, reticulated individuals and skeletal or arborescent formations.

Telluride Gold Ore - Calaverite:

• Color is silver white to brassy yellow.
• Luster is a bright metallic.
• Transparency: Crystals are opaque.
• Crystal System: Monoclinic; 2/m
• Crystal Habits include prismatic to more rarely tabular crystals that are often twinned into sharp bends, reticulated individuals and skeletal or arborescent formations. Also found as granular masses.
• Cleavage is absent.
• Fracture is conchoidal.
• Hardness is 2.5 - 3
• Specific Gravity is approximately 9.1 - 9.3 (very heavy even for metallic minerals).
• Streak is a yellow gray.
• Other Characteristics: Crystals tend to be deeply striated parallel to the prominent length.
• Associated Minerals include gold, quartz, celestite, fluorite, pyrite, nagyagite, sylvanite, krennerite and other rare telluride minerals.
• Notable Occurrences include Cripple Creek in Teller County, Colorado and Calaveras County (from where it gets its name), California, USA; Nagyag, Romania; Kirkland lake Gold District, Ontario and Rouyn District, Quebec, Canada and Kalgoorlie, Australia.
• Best Field Indicators are crystal habit, density, softness, color, luster, association with other tellurides and gold and lack of cleavage:

___________________________

 

_____________________________

INTERNATIONAL BIDDERS:  I welcome international bidders who would want to have these  items shipped to any place in the world.  But please communicate with me BEFORE BIDDING to inquire about shipping and insurance fees.  The "$49.95" shown as the "international shipping charge" is not accurate  -  it is just an example.  The actual international shipping charge would certainly be much less and would depend on how the ore is shipped (First Class, Priority, Express, etc.), where the ore is shipped, and its packaged weight.  Please click on "Ask seller a question" in the top right above to send me a message to ask what the shipping and insurance charge would be to ship the ore to the country where you would want it shipped.  Please allow enough time for me to respond to you before the auction ends!  Thanks!

__________________________

Thank you for looking at this auction!___________________________