Natural Cobalt Spinel 1.25 ct – Pear Cut, Untreated, GIA Certified, Tanzania

Natural Cobalt Spinel 1.25 ct – Pear Cut, Untreated, GIA Certified, Tanzania

Name: Natural Cobalt Spinel 1.25 ct – Pear Cut, Untreated, GIA Certified, Tanzania
Brand: SOSNA Gems & Jewellery
SKU: GP_124802
Price: 276783.00 CZK
Availability: InStock

276.783,00 CZK

Gemstone Specification

Carat Weight 1.25

Dimensions 8.17 x 5.80 x 3.87 mm

Color Blue

Clarity Eye Clean

Shape Pear

Treatment No Treatment

Origin Tanzania

Certification GIA

This natural cobalt spinel weighs 1.25 carats and is cut in a refined pear shape, measuring 8.17 × 5.80 × 3.87 mm. The gemstone displays a vivid and highly desirable blue hue, characteristic of fine cobalt spinels from Tanzania. Certified by GIA, it comes with independent verification of its authenticity and natural properties. The stone is confirmed as unheated and untreated (no indications of enhancement), preserving its original character and rarity. With calibrated dimensions, excellent brilliance, and certified authenticity, this cobalt spinel represents a rare investment-grade gemstone, ideally suited for collectors and bespoke high jewelry designs.

Natural Cobalt Spinel 1.25 ct – Pear Cut, Untreated, GIA Certified, Tanzania

276.783,00 CZK

From gemstone to jewelry

This example illustrates one possible way a gemstone may be developed into a bespoke piece. Final design is always defined individually, based on the stone and its natural character.

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Bespoke jewelry

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Each design is developed individually, guided by the stone, its proportions and natural character.

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Gemological Disclosure

Each gemstone is professionally examined and accompanied by clear gemological information regarding its characteristics, treatments, and origin.

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Gemological overview

Technical and gemological information about this gemstone variety.

Gemological profile

Spinel is a natural magnesium aluminum oxide mineral valued for its excellent transparency, vibrant color range, and clean crystal structure. In gem-quality material, spinel is appreciated for its clarity and lively appearance, with colors ranging from red, pink, and purple to blue, gray, and black, depending on trace elements present during formation.
Chemically composed of magnesium aluminum oxide (MgAl₂O₄), spinel crystallizes in the cubic crystal system and belongs to the oxide mineral group. In transparent gem-quality specimens, it typically displays a vitreous luster with high clarity.
The refractive index of spinel generally ranges from approximately 1.718 to 1.738, producing a bright, balanced brilliance without excessive dispersion. Spinel is found in several regions worldwide, with notable sources including Myanmar, Sri Lanka, Vietnam, Tanzania, and parts of Afghanistan, each associated with slightly different color characteristics.

Durability & suitability

With a hardness of 8 on the Mohs scale, spinel offers very good durability suitable for everyday jewelry when properly set and worn with standard care. Its lack of cleavage contributes to excellent resistance against impact and abrasion compared to many other colored gemstones.
Spinel performs reliably in rings, pendants, earrings, and bracelets, including designs intended for frequent wear. Its combination of durability, stable color, and refined brilliance makes spinel a practical and versatile choice for both everyday jewelry and elegant, statement-oriented designs.

Treatments & authenticity

Spinel is most commonly found in nature without the need for enhancement. Treatments are generally uncommon, and gem-quality spinel is typically valued for its natural color and clarity.
Any treatments or enhancements, if present, are always clearly stated for each individual gemstone. Every stone is professionally examined, and transparent disclosure is regarded as a fundamental part of responsible gemological practice, allowing clients to make informed and confident decisions.

Our approach to gemstones

We focus primarily on natural, untreated gemstones, valued for their authenticity and inherent beauty.
Any treatments or enhancements are always clearly disclosed, allowing our clients to make informed decisions based on transparent gemological standards.

Sosna Gems is not a licensed financial advisor. Gemstones are collectibles, not securities. Past performance is not indicative of future results. Legal & risk disclosure .