Product Description
Natural Swiss Blue Topaz – 16.5 Carats
This listing offers a single loose Swiss Blue Topaz weighing 16.5 carats, cut in a rectangular step cut. The stone measures 16×11×10mm and displays a medium aqua-blue color with strong clarity through its step-cut facets. Origin is Brazil, and the stone has been heat-treated — a standard and stable industry process used to produce the Swiss blue color from colorless or pale natural topaz.
Stone Details
- Stone Name: Topaz – Swiss Blue
- Total Weight: 16.5 carats
- Carat Range: 1–20 carats (filter range)
- Dimensions: 16 × 11 × 10 mm
- Cut / Shape: Step Cut (Rectangular)
- Color: Aqua Blue (Swiss Blue)
- Clarity: VVS – Eye Clean
- Treatment: Heated
- Origin: Brazil
- Deal Type: Single Stone
- Stone Type: Loose / Unmounted
- Gem Classification: Semi-Precious Stone
- Birthstone: November
- Intended Use: Jewelry / Ornament Setting
About Swiss Blue Topaz
Swiss Blue is a specific color grade within the blue topaz category, distinguished by its medium-intensity aqua tone — lighter than London Blue but deeper than Sky Blue. The color is produced through a combination of irradiation and heat treatment applied to natural colorless or pale topaz from Brazil. This treatment is permanent and industry-standard. The step cut used here emphasizes the stone’s transparency and depth of color by reflecting light through its large flat table and parallel facets.
Frequently Asked Questions
What is the difference between Swiss Blue, Sky Blue, and London Blue topaz?
Sky Blue is the lightest shade, Swiss Blue is a medium vivid aqua, and London Blue is the darkest and most saturated. The difference comes from the intensity of treatment applied during production.
Is heat-treated topaz less valuable than untreated topaz?
Heat treatment is the accepted standard for all blue topaz on the market — natural blue topaz is extremely rare. Treated stones are stable, widely used in fine jewelry, and priced based on size, cut quality, and clarity.
What jewelry settings work best for a large step-cut topaz?
Step-cut stones pair well with bezel and four-prong settings that expose the stone’s table. For a 16×11mm size, a cocktail ring, pendant, or brooch setting is most practical.