loading . . . Vote in Round 1 Match 2 It’s a matchup of extremely shiny and geometrically-distinctive ore minerals as soft, greasy Molybdenite faces off against the dark and looming tetrahedrons of Tetrahedrite. Are you championing the molybdenum (and rhenium) ore or the copper (and silver) ore?
Molybdenite from Québec, Canada
flaky hexagon of shiny grey molybdenite embedded in white quartz.
Credit: Eric D. Fritzsch
Molybdenite, powellite, and microcline from New Jersey, USA
An extremely shiny, almost liquid-looking molybdenite vein in a matte orange, green, and white rock.
Credit: Harold Moritz
Molybdenite from Queensland, Australia
A silvery chunk of molybdenite with a crackly texture.
Credit: Marc Gravel
Molybdenite and chalcopyrite from Tasmania, Australia
Flecks of dark grey molybdenite on a speckled tan rock.
Credit: Bob Beattie
Molybdenite from Québec, Canada
A crisp, dark molybdenite hexagon cross section inside clear quartz.
Credit: Kelly Nash
Molybdenite from British Columbia, Canada
Long grey molybdenite crystals at odd angles to each other on a red matrix.
Credit: John Sobolewski
Molybdenite forms greasy, soft silver hexagonal flakes. While this molybdenum ore looks and feels similar to graphite, it is denser, has a more blue tint in its streak when rubbed on paper, and is shinier.
Molybdenite's name comes from μόλυβδοζ, meaning "lead," and was originally used by ancient Greeks to describe a variety of similar soft, grey, shiny minerals including lead ores and graphite. The mineral now known as molybdenite (MoS₂) didn't lay exclusive claim to the name until the late 1700s after the discovery of the element molybdenum. The ore mineral is typically found in high temperature hydrothermal zones.
Molybdenite is the primary ore of molybdenum, which is used to produce high-temperature alloys, and when even small amounts are added to steel alloys it increases toughness, strength, hardness, heat resistance, and corrosion resistance. Molybdenite has a layered structure of alternating sheets of molybdenum and sulfur. This slipperiness and highly fragile perfect cleavage make molybdenite an excellent lubricant and the namesake for LiquiMoly, an additive for high performance motor oils and sponsor of Formula 1 motorsports.
Trace amounts of rhenium substitute for molybdenum, with concentrations reaching up to 1 to 2%, high enough to be a valuable byproduct of processing molybdenite. Rhenium is used in metal alloys in wind turbines and automobile catalysts. The parent/daughter ratio of radioactive isotope rhenium-187 and osmium-187 make molybdenite useful for geochronology and dating geologic timescales.
Ingesting small amounts of molybdenite is normal, and even an essential nutrient for human health, but it can be hazardous in larger quantities. While it can be used as a fertilizer, do not eat fistfuls of molybdenite-rich dirt. Huffing molybdenite dust is similarly discouraged.
Molybdenite's role in producing durable steels for wind turbines, pipelines, and electric vehicle infrastructure makes it indispensable in the transition toward renewable energy systems, ensuring that molybdenite will remain a critical industrial mineral for decades to come.
Tetrahedrite and quartz from Pasco, Peru
Dark cool grey tetrahedrite crystals with some iridescent faces.
Credit: Harold Moritz
Tetrahedrite from Pasco, Peru
A craggy mass of blocky tetrahedrite crystals with a lot of cool-toned iridescence.
Credit: Harold Moritz
Tetrahedrite, siderite, quartz, and sphalerite from Czech Republic
Black tetrahedrite points and clear quartz points with a sprinkling of other yellowish minerals. The tetrahedrite has a streaky texture.
Credit: Harold Moritz
Tetrahedrite, siderite, and sphalerite from Huancavelica, Peru
Blue-black tetrahedrite chunks with yellowish siderite and sphalerite along the sides.
Credit: Kelly Nash
Tetrahedrite, rhodochrosite, and quartz from Ancash, Peru
Shiny black tetrahedrite peeking out amongst rosy pink rhodochrosite.
Credit: Tony Peterson
Tetrahedrite from Colorado, USA
Tetrahedrite with a silvery and slightly iridescent sheen.
Credit: Eric D. Fritzsch
Tetrahedrite forms dark metallic crystals with a striking tetrahedral shape. It's appearance inspired both a former and current name: originally German "fahl" for ash-coloured and "erz" for ore in tribute to its colour, falherz was renamed in 1845 by Wilhelm Karl von Haidinger to acknowledge its distinctive shape.
Tetrahedrite is a mineral subgroup, a collection of minerals that share a similar structure but with variations in their chemical composition. The tetrahedrite subgroup contains at least 7 distinct named minerals, all following the chemical formation of a copper antimony sulfosalt (Cu₆[Cu₄ (X)₂]Sb₄ S₁₃) where the final element X can be Fe2+, Zn, Cd, Hg, or other elements. Silver can also substitute in for copper, often up to several percent by weight. While less abundant than some other copper ores, tetrahedrite's potential to extract silver along with copper make it economically attractive. This dual purpose ore is recognized in the video game Dwarf Fortress, where smelting tetrahedrite nuggets produces a mix of copper and silver bars. Antimony, mercury, or arsenic-bearing tetrahedrite can complicate ore processing as the heavy metals pose health and environmental hazards.
Tetrahedrite forms in low to moderate temperature hydrothermal veins and contact metamorphic deposits. Sulfosalts like tetrahedrite have some of the complicated crystal structures, and this may be in part because lower temperatures allow the metal atoms have a higher degree of ordering during crystallization.
With its dual potential as both a copper and silver ore, this mineral plays an understated but meaningful role in our past and future. Copper and silver are both highly prized for their beauty and utility, with copper's contribution as a backbone of electrical wiring, renewable energy grids, and electric vehicle production essential to the Green Energy Transition.
Molybdenite ran in Mineral Cup 2025, where it was defeated during round 2 by semifinalist dioptase. Tetrahedrite has never competed in Mineral Cup.
#OreCup Round 1 Match 2 *
Molybdenite
Tetrahedrite
Thank you!
**Please vote only once per player.** Multiple players may vote using the same device. **Voting for each match starts and ends at 00:00 GMT.** Due to site limitations, the polls will continue to be visible, but only votes cast in the 24-hour period will be tallied.
time remaining https://www.mineralcup.org/vote-results/vote-r1m2
