0.64 ct Natural Heated Blue Sapphire – Round (approximately 5mm) Cut | Sri Lanka (Ceylon)

A natural 0.64 carat blue sapphire in a round shape with Flower Cut faceting, from Sri Lanka (Ceylon), heat treated and certified by AGCL (Arctic Gem Certification & Laboratory), Report #M263600. At approximately 5mm in diameter, this round Ceylon blue sapphire is a calibrated format — the 5mm size fits a standard range of round settings in earring, pendant, and ring applications without custom fabrication. Ceylon origin adds the documented quality associated with Sri Lanka's fine sapphire production, and the Flower Cut faceting delivers vivid blue display for this carat weight.

Rarity Analysis

Ceylon blue sapphire is one of the most recognized gemstone colors in the world, but not every stone marketed as "Ceylon blue" shares the same combination of color, cut, and documentation. Here's how this 0.64 ct stone stacks up.

• Color: classic Ceylon blue, the most recognized sapphire color
• Size: at 0.64 ct this is a compact accent/small-centerpiece size
• Treatment: heated — standard, disclosed
• Clarity: Eye-clean
• Documentation: AGCL Report #M263600 confirms species, carat weight, and heat treatment; Sri Lanka (Ceylon) origin is stated by Crescent Gems as part of the listing rather than a separate origin-only lab finding
• Combined effect: genuine Ceylon color, a faceting style built for brightness, and full treatment disclosure combine to make this a well-documented, honestly represented stone at an accessible price point

Buying Guidance

A few things to weigh before adding this stone to your cart:

• Setting Compatibility: the calibrated ~5mm round diameter fits standard round settings without custom sizing, simplifying ring, pendant, or earring fabrication
• Pairing for Earrings: if you need a matching pair, contact Crescent Gems before purchase to check for a closely matched second stone
• Treatment Disclosure: this stone is heat treated, a widely accepted and industry-standard practice for sapphires that improves color and clarity — always confirm treatment status on any sapphire you're comparing
• Documentation Review: request or review AGCL Report #M263600 before purchase to confirm carat weight, dimensions, and treatment match the listing
• Try Before You Buy: Crescent Gems offers a 14-day return window from delivery, so you can view the stone in hand before committing it to a finished piece

Learn More About This Gemstone

• How to Buy Natural Sapphires Online: What to Check, What to Avoid, and What Certification Actually Tells You
• How to Commission a Custom Ring — From Loose Stone to Finished Piece
• The Ultimate Guide to Buying Natural Loose Sapphires
• Blue Sapphire — The Complete Buyer's Guide to Color, Origin, and Value
• How Sapphire Heat Treatment Works — Temperature, Process, and What Changes Inside the Stone

Why Choose this 0.64 ct Round Ceylon Blue Sapphire?

Ceylon blue sapphire at 0.64 carats in a calibrated round is the most practical format for earring center stones and small pendant solitaires that require a vivid blue sapphire with documented origin. The Flower Cut faceting maximizes color display for the weight, and the ~5mm calibrated diameter eliminates the sizing and fitting steps that uncalibrated stones require in production.

Key Benefits of this Natural Blue Sapphire

• Ceylon Origin
  Sri Lanka — the benchmark source for vivid blue sapphire at the commercial level.
• Calibrated ~5mm Format
  Consistent diameter for drop-in use in standard round solitaire earring and pendant settings.
• Flower Cut Sparkle
  Maximum light return for this carat weight from the flower-pattern faceting — vivid Ceylon blue face-up.
• Earring and Pendant Scale
  0.64 carats — the right weight for earring center stones and small pendant solitaires.
• Durable for Daily Wear
  Corundum at Mohs 9, second only to diamond.

Features

• Carat Weight: 0.64 Carats
• Gem Type: Natural Blue Sapphire
• Variety: Blue Sapphire
• Shape: Round
• Cut Style: Flower Cut
• Dimensions: 4.98 x 4.96 x 3.43 mm
• Origin: Sri Lanka (Ceylon)
• Treatment: Heat Treated
• Color: Blue (Ceylon Blue)
• Clarity: Eye-clean — no visible inclusions under normal viewing
• Hardness: 9 on the Mohs scale
• Certification: AGCL Gemstone Report #M263600

This 0.64 ct round Ceylon blue sapphire has been hand-selected for the vividness of its blue — the quality that delivers consistent Ceylon character in earring and pendant applications.

One of a Kind

This is a single natural gemstone, not a manufactured or lab-created replica — no two sapphires form with identical color, clarity, and internal character. Once this stone sells, it's gone; there is no duplicate. What you see documented on the AGCL report is the exact, individual stone you receive.

Care

Sapphire is exceptionally durable (Mohs 9), but a few habits keep it looking its best. Clean with warm water, mild soap, and a soft brush; avoid ultrasonic or steam cleaners if the stone is set alongside softer or treatment-sensitive materials. Store separately from other jewelry to prevent surface scratches to softer pieces, and remove the stone before swimming, exercising, or household chemical exposure. Heat-treated color is stable under normal wear, but avoid sudden extreme temperature changes and prolonged direct heat.

Why Customers Love This Gemstone

• Ceylon Blue Quality: The benchmark blue at an earring-friendly weight.
• Calibrated Round: Fits standard ~5mm settings without adjustment.
• Daily Wear Durability: Mohs 9 — appropriate for all jewelry types.
• Trusted Source: Ceylon origin confirmed, treatment disclosed honestly, and independently certified by AGCL (Report #M263600).

Owning this 0.64 ct round Ceylon blue sapphire means choosing the most recognized sapphire quality in a calibrated earring and pendant format.

Perfect Uses for this 0.64 ct Blue Sapphire

• Solitaire stud earrings (pair)
• Small pendant solitaire
• Three-stone ring center stone
• September birthstone jewelry
• Accent stone in custom multi-stone design