Natural aquamarine, 4.20 carats, cushion cut, IF clarity, untreated, slightly bluish green, ČGL certified

Natural Aquamarine 4.20 ct – Cushion Cut, Untreated, ČGL Certified

Name: Natural Aquamarine 4.20 ct – Cushion Cut, Untreated, ČGL Certified
Brand: SOSNA Gems & Jewellery
SKU: 22-01-032
Price: 12890.00 CZK
Availability: InStock

12.890,00 CZK

This 4.20 carat natural aquamarine displays a delicate slightly bluish-green hue, cut into a refined cushion shape measuring 11.47 × 9.18 × 6.97 mm. With internally flawless (IF) clarity, the gemstone offers outstanding transparency and brilliance, a rare feature in aquamarines of this size. Untreated and entirely natural, it retains its purity and authenticity. Certified by the Czech Gemological Laboratory (ČGL), the gemstone comes with independent verification of origin and quality. Its flawless clarity, elegant cushion cut, and certified authenticity make it an exceptional choice for fine jewelry designs or as a highlight in a curated gemstone collection.

12.890,00 CZK

From gemstone to jewelry

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Gemological overview

Technical and gemological information about this gemstone variety.

Gemological profile

Aquamarine is a blue to blue-green variety of beryl, appreciated for its clear, fresh coloration and natural transparency. Within the beryl family, it is valued for its calm visual character and refined appearance, particularly in well-cut stones with even color distribution.
Chemically composed of beryllium aluminum silicate (Be₃Al₂Si₆O₁₈), aquamarine crystallizes in the hexagonal crystal system and belongs to the silicate mineral group. In gem-quality specimens, it typically displays a vitreous luster and high transparency.
The refractive index of aquamarine generally ranges from 1.577 to 1.583, contributing to a subtle, elegant brilliance rather than strong dispersion. Aquamarine is found in several regions worldwide, with typical sources including Brazil, Madagascar, Mozambique, Nigeria, and Pakistan, each known for slightly different tonal qualities.

Durability & suitability

Aquamarine is a blue to blue-green variety of beryl, appreciated for its clear, fresh coloration and natural transparency. Within the beryl family, it is valued for its calm visual character and refined appearance, particularly in well-cut stones with even color distribution.
Chemically composed of beryllium aluminum silicate (Be₃Al₂Si₆O₁₈), aquamarine crystallizes in the hexagonal crystal system and belongs to the silicate mineral group. In gem-quality specimens, it typically displays a vitreous luster and high transparency.
The refractive index of aquamarine generally ranges from 1.577 to 1.583, contributing to a subtle, elegant brilliance rather than strong dispersion. Aquamarine is found in several regions worldwide, with typical sources including Brazil, Madagascar, Mozambique, Nigeria, and Pakistan, each known for slightly different tonal qualities.

Treatments & authenticity

With a hardness of 7.5 to 8 on the Mohs scale, aquamarine offers good durability suitable for everyday jewelry when properly set and worn with standard care. It performs reliably across a wide range of jewelry designs, including rings, pendants, earrings, and bracelets.
While aquamarine is generally resistant to everyday wear, larger stones or more exposed settings benefit from protective designs to reduce the risk of impact. Its combination of durability, clarity, and naturally soothing color makes aquamarine a versatile choice for both everyday jewelry and elegant, understated statement pieces.

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 .