Natural Amethyst 8.50 ct – Bicolor, Octagonal Cut, Untreated

Natural Amethyst 8.50 ct – Bicolor, Octagonal Cut, Untreated

4.542,00 CZK

Gemstone Specification

Carat Weight 8.5

Dimensions 16.00 x 10.00 x 7.00 mm

Color Purple - Bicolor

Clarity Eye Clean

Shape Octagonal

Treatment No Treatment

Certification Basic Seller's Certificate

This 8.50 carat natural bicolor amethyst features a refined octagonal cut and an intriguing transition of purple tones that make it truly distinctive. Eye clean and untreated, the gem showcases natural color zoning that highlights its uniqueness. Perfect for a one-of-a-kind custom jewelry piece. Comes with a standard seller’s certificate; GIA or IGI certification available upon request for an additional fee.

Natural Amethyst 8.50 ct – Bicolor, Octagonal Cut, Untreated

4.542,00 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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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

Amethyst is a violet to purple variety of quartz, recognized for its natural color range and consistent availability in gem-quality material. Within the quartz family, it is one of the most established and historically used gemstones, appreciated especially in larger sizes where color distribution and clarity can be fully evaluated.
Chemically composed of silicon dioxide (SiO₂), amethyst belongs to the silicate mineral group and crystallizes in the trigonal crystal system. In gem-quality specimens, it typically displays a vitreous luster and transparent clarity.
The refractive index of amethyst generally ranges from 1.544 to 1.553, resulting in a soft, balanced brilliance rather than sharp sparkle.
Amethyst is mined in several regions worldwide, with typical sources including Brazil, Uruguay, Zambia, and Madagascar, each known for slightly different color characteristics.

Durability & suitability

With a hardness of 7 on Mohs scale, amethyst offers solid durability suitable for everyday jewelry when properly set and worn with standard care. It performs reliably in a wide range of designs, particularly in pendants, earrings, and bracelets, where the stone is less exposed to direct impact.
While amethyst can be used in rings, it is best suited for settings that provide adequate protection, especially for larger stones. Its combination of durability, availability in generous sizes, and visually calming color makes it a versatile choice for both everyday pieces and more expressive, statement-oriented jewelry designs.

Treatments & authenticity

Amethyst is commonly found in nature without the need for enhancement. In some cases, gentle heat treatment may be applied within the gem trade to stabilize or refine color, a practice that is widely accepted when properly disclosed.
Any treatments or enhancements are always clearly stated for each individual gemstone. Every stone is professionally examined, and transparent disclosure is considered 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 .