Fluorescent Ruby Corundum with Blue Kyanite in Quartz – Minas Gerais, Brazil – 0.78 lbs

A remarkable Fluorescent Ruby Corundum with Blue Kyanite in Quartz specimen from Minas Gerais, Brazil, featuring dense sprays of bladed blue kyanite distributed across a substantial quartz-rich formation. Mounted upright on a custom display base, the specimen presents a broad crystallized face with strong color, layered texture, and impressive cabinet presence.

Under ordinary lighting, numerous pale blue to medium-blue kyanite blades overlap and intersect throughout the formation. Many display pronounced lengthwise striations, flat reflective surfaces, and naturally irregular terminations. Colorless-to-milky quartz fills the spaces between the blades, creating bright contrast while preserving openings and recessed areas that give the specimen considerable three-dimensional depth.

The specimen transforms dramatically beneath ultraviolet illumination. Large portions of the bladed formation produce vivid pink, magenta, and red fluorescence, with selected areas appearing especially intense. This response is consistent with chromium-bearing material within the association. Chromium can produce red fluorescence in both ruby corundum and some kyanite; without analytical mapping, the exact contribution of each mineral cannot be separated from photographs alone. The corundum identification and Brazilian locality are presented according to the supplied provenance.

The ultraviolet response also reveals zoning and growth patterns that are far less apparent under ordinary lighting. Individual blades, intersecting crystal groups, and internal structures become outlined in contrasting pink-red and blue-white tones, giving the specimen two dramatically different display appearances.

Measuring approximately 4 × 1.5 × 3 inches and weighing 0.78 pounds, this is a substantial mounted cabinet specimen. Its combination of abundant blue kyanite, ruby-bearing corundum association, quartz matrix, intense UV response, and attractive elevated presentation makes it an excellent centerpiece for a fluorescent-mineral or Brazilian mineral collection.

Specifications

Minerals: Blue Kyanite, Ruby-Bearing Corundum, and Quartz

Locality: Minas Gerais, Brazil

Weight: 0.78 lbs (approximately 354 grams)

Dimensions: Approximately 4 × 1.5 × 3 inches

Color Under White Light: Pale blue to medium blue, colorless, milky white, cream, and gray

Fluorescence: Strong pink, magenta, and red response across substantial portions of the formation

UV Disclosure: Fluorescent color and intensity may vary according to UV wavelength, lamp strength, ambient lighting, exposure, and camera settings

Crystal Habit: Flattened and elongated kyanite blades with pronounced longitudinal striations

Associated Material: Quartz-rich matrix with corundum identified according to supplied provenance

Kyanite Chemical Formula: Al₂SiO₅

Corundum Chemical Formula: Al₂O₃

Quartz Chemical Formula: SiO₂

Kyanite Crystal System: Triclinic

Corundum Crystal System: Trigonal

Quartz Crystal System: Trigonal

Luster: Vitreous to pearly kyanite, vitreous quartz, and naturally coated areas

Transparency: Translucent to opaque with selected light-transmitting edges

Mounting: Affixed to a custom display base produced in-house

Display: Elevated upright cabinet specimen

Condition: Natural mineral specimen with inherent contacts, cleavage, incomplete blades, surface coatings, matrix attachments, extraction-related irregularities, and minor edge wear

Exact specimen shown

About Kyanite, Ruby Corundum, and Fluorescence

Kyanite is an aluminum silicate mineral that forms under high-pressure metamorphic conditions. It commonly develops as elongated, flattened blades and is especially recognizable by its blue coloration, prominent cleavage, and lengthwise striations.

Kyanite has strongly directional hardness. Its resistance to scratching differs depending on the direction in which it is tested, an unusual property that historically led to the name “disthene,” meaning two strengths.

Ruby is the chromium-bearing red variety of corundum. Corundum consists primarily of aluminum oxide, while small amounts of chromium can produce pink-to-red coloration and powerful red fluorescence. Chromium may also substitute for aluminum within some kyanite, allowing blue kyanite itself to produce a red response under certain ultraviolet wavelengths.

Because both minerals can potentially contribute to the observed response, fluorescence alone should not be treated as definitive proof that every glowing blade is ruby. The vivid reaction nevertheless provides excellent evidence of chromium-bearing mineralization within the specimen. GIA confirms that chromium is responsible for ruby’s red coloration and can also produce its characteristic red fluorescence. (GIA)

Quartz forms the pale supporting matrix, providing visual contrast and helping preserve the complex arrangement of kyanite blades. Minas Gerais is internationally celebrated for its diverse metamorphic and pegmatitic mineral deposits, which have produced many important quartz, corundum, kyanite, tourmaline, and associated collector specimens.

Collector Notes

This specimen features:

• Natural mineral association from Minas Gerais, Brazil
• Dense coverage of pale-to-medium blue kyanite
• Numerous elongated and flattened crystal blades
• Pronounced longitudinal crystal striations
• Ruby-bearing corundum association based on provenance
• Contrasting colorless-to-milky quartz matrix
• Strong pink, magenta, and red UV fluorescence
• Extensive fluorescent coverage rather than isolated points
• Visible fluorescent zoning and crystal-growth patterns
• Dramatically different appearances under white light and UV
• Strong three-dimensional intergrowth
• Multiple attractive viewing angles
• Substantial 0.78-pound cabinet size
• Custom display base produced in-house
• Elevated, ready-to-display presentation
• Exact specimen pictured

Perfect for collectors of fluorescent minerals, blue kyanite, ruby corundum, ruby-bearing matrix specimens, Brazilian minerals, Minas Gerais specimens, chromium-bearing minerals, mounted cabinet specimens, and unusual metamorphic mineral associations.

Kyanite possesses excellent cleavage and individual blades can be fragile. Always handle the specimen by its display base and avoid pressure on projecting crystals.

Professionally packaged and shipped from Colorado.

You will receive the exact specimen shown.

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