Overview

Molybdenite (MoS2) is the primary ore of molybdenum and a quintessential “metallic paper” mineral for collectors. It forms soft, silvery steel-gray hexagonal plates and rosettes with a brilliant metallic sheen and a subtle blue tint. Plates often show crisp hexagonal outlines, radial “snowflake” rosettes, and fine lamellar striations. On bright white quartz, fluorite, or feldspar matrix, molybdenite’s mirror-like plates provide dramatic contrast. While not colorful, its geometric perfection, reflective luster, and iconic rosette habit make fine specimens highly aesthetic.

Physically, molybdenite is very soft (Mohs ~1–1.5), sectile, and flexible; it cleaves into ultra-thin sheets like graphite and readily leaves gray marks. This fragility makes pristine plates and undisturbed rosettes notably hard to find and especially prized when well-positioned on clean, undamaged matrix.

Popularity

Collectors prize molybdenite for:

• Geometry and luster: Sharp hexagonal plates and showy rosettes with a bright metallic sheen.
• Contrasts and associations: Superb combinations with quartz, fluorite, scheelite, cassiterite, feldspar, and muscovite are sought-after.
• Classic provenance: Legendary porphyry-molybdenum mines like Climax and Henderson (Colorado) and modern Chinese tungsten districts (Hunan, Sichuan) set quality benchmarks.

Although industrial mining has produced abundant molybdenite, fine display pieces are less common due to extraction damage and the mineral’s softness. Top examples—undamaged, sharply hexagonal rosettes on contrasting matrix—remain scarce and command strong interest among systematic and aesthetic collectors alike.

Top Collecting Localities

Below are renowned sources that have yielded distinctive, collectible molybdenite. Each locality is selected from the ID database so you can browse and compare verified examples.

Collector’s Guide

Evaluating Specimen Quality

• Color and Luster: The best molybdenite shows a bright steel-gray to silvery-blue metallic sheen. Fresh, reflective faces and clean cleavage surfaces are key; dull, rubbed, or smeared plates are less desirable.

• Crystal Form and Habit:

  • Hexagonal plates with sharp outlines and visible, concentric lamellae are classic.
  • Rosettes (“snowflakes”) with radial symmetry add strong aesthetic appeal.
  • Thickness matters: plates should be neither so thin that edges fray nor so thick that symmetry looks clumsy.
  • Orientation counts—plates tilted toward the viewer on contrasting matrix (quartz, fluorite, feldspar) display best.

• Condition:

  • Molybdenite is very soft and flexible; edges chip and abrade easily. Inspect for rubbed rims, missing segments, or delamination.
  • Look for intact, undisturbed rosettes and minimal edge wear. Even tiny brushes can leave marks, so pristine surfaces command a premium.
  • Check matrix for stability—crumbly hosts shed dust that scuffs plate faces.

• Associations and Aesthetics:

  • High-contrast pairings (e.g., mirror-bright molybdenite on clear quartz or mint-fluorite) elevate display value.
  • Attractive combos with scheelite, cassiterite, apatite, muscovite, and pyrite are sought-after.
  • Balance, composition, and a primary viewing angle with minimal distractions (contacts, stains) earn points.

• Size:

  • Larger plates/rosettes are uncommon in fine condition; value rises quickly with size if edges remain crisp and luster strong.

Detecting Repairs or Treatments

• Reattachments and Stabilization:

  • Plates or rosettes sometimes detach and are re-glued. Examine junctions and plate bases under magnification for hairline adhesive films, slight misalignments, or glue sheen. Some epoxies fluoresce under longwave UV.
  • In fragile clusters, preparators may use consolidants (e.g., Paraloid) to reduce shedding. Over-application can leave a slightly plasticky gloss not typical of natural lamellae.

• Cleaning Artifacts:

  • Abrasive cleaning leaves micro-scratches and dulled luster; rubbed edges appear matte or “feathered.”
  • Strong oxidizers (e.g., hydrogen peroxide) can alter surfaces and encourage yellowish molybdite alteration on edges—avoid.

• Polishing/Coating:

  • True polishing of molybdenite plates is rare (and risky) but would leave an unnaturally uniform mirror surface and softened micro-texture. Any coating that changes the feel or reflectivity should be disclosed.

In general, minor, well-executed reattachments on significant pieces can be acceptable if disclosed; heavy stabilization or assembled composites are less desirable.

Care and Storage

Molybdenite demands gentle, thoughtful care due to its softness and perfect cleavage.

• Handling:

  • Support the matrix; avoid touching plates. Even a soft brush can abrade surfaces.
  • Do not flex or press plates—delamination is easy and irreversible.
  • For transport, immobilize the specimen in foam so no vibration can make plates rub.

• Cleaning:

  • Prefer air bulbs or very gentle puffs of clean air; avoid compressed air at close range (it can lift flakes).
  • If absolutely necessary, rinse lightly with distilled water and let dry—no rubbing. Avoid detergents, ultrasonic cleaners, steam, acids, or oxidizers.
  • Never use solvents or aggressive chemicals; they can undercut any adhesives and encourage alteration to yellow molybdite on edges.

• Environment:

  • Room temperature and normal humidity are fine. Keep away from vibration, friction, and stacking where plates could scrape.
  • Avoid prolonged exposure to corrosive or acidic fumes (e.g., near lab acids) which may lead to surface alteration over time.
  • Light does not typically affect color, but place out of direct sun to minimize heating and dusting frequency.

• Storage and Display:

  • Covered cases or dustproof boxes protect the delicate surfaces.
  • Isolate from harder or abrasive specimens; a tiny nudge from quartz or feldspar can scratch plates.
  • If a specimen has known stabilization (e.g., consolidant), avoid heat or solvents that might compromise it.

Treat molybdenite like you would a fine graphite drawing: protect from touch, abrasion, and harsh cleaning. With careful handling and soft, dust-free storage, the metallic luster and sharp geometry will endure for decades.