Cupromakopavonite

Chemical formula: Cu₁+₈Ag₁+₃Pb₂+₄Bi₃+₁₉S₂-₃₈

A very rare sulfide of copper, silver, lead, and bismuth, forming microscopic, metallic inclusions in other sulfides.

## Characteristics Cupromakopavonite is a complex sulfide with a metallic appearance. It occurs as very fine, anhedral (not exhibiting its own crystallographic form) grains, usually not exceeding 100 micrometers in size. It is most commonly found as inclusions in galena or as a component of mineral mixtures with other bismuth sulfides. Its observation and identification require the use of a reflected light microscope. ## Physical Properties Due to the microscopic size of the grains, most physical properties, such as hardness, density, or fracture, have not been precisely determined for macroscopic samples. The mineral exhibits a strong metallic luster in reflected light. ## Colors and Varieties In reflected light under the microscope, cupromakopavonite has a creamy white color. No color varieties or commercial varieties have been observed for it. ## History and Name The name "cupromakopavonite" reflects its chemical composition and its relation to the pavonite structure. The prefix "cupro-" indicates the dominance of copper (Latin: *cuprum*) over silver, and the suffix "-makopavonit" refers to makovieckyite and pavonite, minerals with a similar crystal structure. It was approved as a new mineral by the International Mineralogical Association (IMA) in 1997.

Properties

Luster: Metallic
Transparency: Opaque
Crystal system: Monoclinic

Diagnostic features

## Identification Identification of cupromakopavonite is possible only through advanced laboratory techniques. It requires optical analysis in reflected light on a polished section and confirmation of chemical composition using an electron microprobe (EDS/WDS). ## Distinguishing from Similar Minerals Under the microscope, it can be confused with many other bismuth sulfides and sulfosalts, such as pavonite, makovieckyite, galenobismutite, or aikinite. Certain differentiation is possible only on the basis of chemical analysis. ## Crystal Forms This mineral forms exclusively anhedral, irregular grains and aggregates, most often as inclusions in other minerals, mainly galena.

Geological environment

## Genesis Cupromakopavonite forms under hydrothermal conditions, in ore deposits rich in bismuth, lead, silver, and copper. It crystallizes in the late stages of ore vein formation. ## Mineral Associations It most commonly co-occurs with galena (as inclusions), native bismuth, bismuthinite, aikinite, pavonite, makovieckyite, matildite, and quartz. ## Localities The type locality and one of the main known occurrences is the Sn-W-Bi-Mo deposit in the Vykmanov-Krupka area in the Ore Mountains (Krušné Hory) in the Czech Republic. It has also been reported in other, few locations worldwide with similar geology.

Rarity

Extremely rare

For collectors

## Quality Criteria From a collector's perspective, the value of a cupromakopavonite specimen lies not in its aesthetics, but in its scientific value and rarity. The most valuable are polished sections with well-documented and identified presence of this mineral, originating from the type locality. ## Popular Localities The only significant source of specimens for research and advanced collections is the Krupka region in the Czech Republic.

Care and storage

## Cleaning Due to its occurrence as microscopic inclusions in polished sections, these specimens do not require and should not be cleaned in a traditional manner. ## What to Avoid Avoid all chemicals, ultrasonics, and abrasion of the polished surface, as this can irreversibly damage the delicate mineral inclusions. ## Storage Microscopic polished sections should be stored in special boxes that protect the polished surface from dust and scratches.

Sources

IMA Mineral List (CNMNC)