Monumental Fluorescent Dogtooth Calcite Formation – Sweetwater Mine, Missouri, USA – 30.37 lbs

A monumental Fluorescent Dogtooth Calcite Formation from the Sweetwater Mine in Reynolds County, Missouri, featuring an extraordinary landscape of large scalenohedral calcite crystals rising from substantial natural matrix. Weighing more than 30 pounds and standing approximately 14 inches tall, this is a genuine statement-sized American mineral specimen with commanding architectural presence.

The formation is covered with numerous intergrown dogtooth calcite crystals ranging from broad, substantial points to smaller secondary growth. These sharply tapered scalenohedrons project in multiple directions, creating deep valleys, elevated crystal ridges, and an almost fortress-like silhouette. Crystallization continues across much of the specimen, providing several viable display angles and revealing new formations as the piece is rotated.

Under ordinary lighting, the calcite displays earthy cream, tan, amber, gray, and dark brown coloration. Natural iron staining, mineral coatings, inclusions, contacts, cleavage features, and irregular growth surfaces preserve the rugged character of the formation and contrast beautifully with its more reflective crystal faces.

The specimen becomes dramatically different under ultraviolet illumination. Distinct areas produce alternating red-to-orange and blue-to-blue-white fluorescence, outlining individual crystals and mineralized zones across the formation. Some sections glow intensely red while neighboring areas respond in bright blue-white, creating an exceptional multicolored fluorescent display. The precise appearance and intensity may vary with the wavelength, strength, and type of UV light used.

The Sweetwater Mine is internationally recognized among collectors for its calcite, galena, marcasite, chalcopyrite, and associated Mississippi Valley–type mineralization. Although the locality is especially famous for the trade-named “Dragon Scale Calcite,” this specimen exhibits a predominantly classic dogtooth or scalenohedral crystal habit rather than the distinctive phantom-like Dragon Scale style.

Measuring approximately 10 × 10 × 14 inches and weighing 30.37 pounds, this specimen is substantially larger than the majority of Sweetwater calcite formations available to private collectors. Its remarkable scale, complex crystallization, locality significance, multidirectional structure, and contrasting fluorescent responses make it an important display piece for a serious mineral collection, gallery, museum-style exhibit, office, showroom, or fluorescent-mineral display.

Specifications

Mineral: Calcite

Formation: Monumental intergrown dogtooth calcite cluster on natural matrix

Crystal Habit: Scalenohedral or “dogtooth” calcite crystals

Locality: Sweetwater Mine, Ellington, Reynolds County, Missouri, USA

Mining District: Viburnum Trend

Weight: 30.37 lbs (approximately 13.78 kg)

Dimensions: Approximately 10 × 10 × 14 inches

Color under White Light: Cream, tan, amber, gray, dark brown, and nearly black

Fluorescence: Alternating red-to-orange and blue-to-blue-white fluorescent zones

UV Disclosure: Fluorescent color and intensity may vary according to UV wavelength, lamp strength, ambient lighting, and viewing conditions

Crystal Habit: Large tapered scalenohedrons with extensive intergrown secondary crystallization

Luster: Vitreous to subvitreous with naturally coated areas

Transparency: Translucent to opaque with selected light-transmitting crystal edges

Crystal System: Trigonal

Chemical Formula: CaCO₃

Mohs Hardness: Approximately 3

Matrix: Substantial natural mineralized host matrix

Display Coverage: Extensive crystallization across multiple sides

Display: Large, naturally self-supporting statement specimen

Condition: Natural mineral specimen with inherent contacts, cleavage, incomplete or contacted terminations, inclusions, surface coatings, iron staining, extraction-related irregularities, and minor edge damage consistent with its exceptional size and geological origin

Handling: Requires two-person handling and a strong, stable display surface

Exact specimen shown

About Sweetwater Mine Calcite

Calcite is a calcium carbonate mineral that crystallizes in the trigonal crystal system. It develops in an exceptionally wide range of habits, including rhombohedrons, flattened plates, prismatic crystals, and sharply tapered scalenohedrons. The elongated pointed crystals visible throughout this specimen are commonly described by collectors as dogtooth calcite.

The Sweetwater Mine is part of southeastern Missouri’s Viburnum Trend, an important Mississippi Valley–type lead-zinc mining district. Mineral-rich fluids circulated through carbonate rock, producing deposits containing galena, sphalerite, calcite, dolomite, marcasite, chalcopyrite, and other associated minerals.

Sweetwater is especially celebrated for its large calcite crystals and the visually distinctive material marketed as Dragon Scale Calcite. Dragon Scale specimens typically exhibit recognizable internal zoning or phantom-like patterns resembling overlapping scales. While this specimen comes from the same famous locality, its dominant crystal habit is more accurately described as dogtooth or scalenohedral calcite.

Fluorescence occurs when a mineral absorbs ultraviolet energy and releases part of that energy as visible light. Different trace elements, structural defects, mineral inclusions, and generations of calcite growth can produce noticeably different responses. The alternating red and blue fluorescent regions on this formation visually reveal variations that are much less obvious under normal illumination.

Calcite possesses perfect cleavage and is considerably softer than quartz. This specimen should not be soaked, exposed to acids, or cleaned with harsh chemicals. Use a soft dry brush or carefully controlled low-pressure air when necessary. Due to its weight and projecting crystals, it should always be lifted from beneath the matrix rather than by any crystal point.

Collector Notes

This specimen features:

• Monumental 30.37-pound display size
• Authentic Sweetwater Mine provenance
• Classic American mineral locality
• Extensive dogtooth calcite crystallization
• Numerous large, tapered scalenohedral crystals
• Smaller secondary crystals covering much of the formation
• Complex architectural and fortress-like silhouette
• Strong three-dimensional structure
• Several attractive display orientations
• Alternating fluorescent mineral zones
• Red-to-orange fluorescence across substantial areas
• Contrasting blue-to-blue-white fluorescent response
• Dramatic transformation between white light and UV illumination
• Natural iron staining and earthy mineral coatings
• Preserved contacts, cleavage features, and growth textures
• Substantial natural host matrix
• Exceptional size compared with typical Sweetwater specimens
• Strong American-mineral and locality-collector appeal
• One-of-a-kind natural mineral formation
• Exact specimen pictured

Perfect for collectors of Sweetwater Mine minerals, Missouri calcite, dogtooth calcite, scalenohedral calcite, fluorescent minerals, American minerals, Viburnum Trend specimens, monumental mineral formations, statement crystals, museum-style displays, and significant locality specimens.

Due to its exceptional size, weight, and projecting crystals, this specimen requires specialized protective packaging and careful handling. Please verify shipping or pickup arrangements before purchase.

Professionally packaged and shipped from Colorado.

You will receive the exact specimen shown.

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