✨ Fascinating Facts About Gemstone Cutting & How Sapphires Are Transformed
I’ve been meaning to share this for a while—and what better time than now? Customers often ask how our natural sapphires go from rough crystals to dazzling gems, and the truth is, it’s a journey filled with precision, skill, and artistry. Here's a behind-the-scenes look at how our Ceylon sapphires are processed—from mine to masterpiece.
🔹 Step 1: The Rough Sapphire
Natural sapphires start their journey in various geological environments, either mined from underground or found in riverbeds. Their shapes vary depending on where they’re discovered. Riverbed sapphires usually look like smooth pebbles, while underground gems often have sharp, fractured edges.
These raw stones are rarely flawless—inclusions and internal features are part of their natural beauty, and a clear indicator that the gemstone is not synthetic. We inspect each rough sapphire for color, clarity, and potential before cutting—using water or oil to reveal internal features.
Fact 1: Only 5% of a mine’s output generates 95% of its value. That’s why top-quality sapphires are so rare and highly prized.
📌 Fun Fact: In Sri Lanka, exporting rough gemstones is not permitted. All stones must be cut locally, supporting skilled artisans and maintaining value transparency.
Thanks to my Sri Lankan background, we’re able to access exceptional sapphires first hand and share them with you.
🔹 Step 2: Preforming the Stone
Most sapphires aren’t evenly colored. Instead, they have color zones or patches, so the cutter’s job is to position that color for maximum effect in the final stone.
To do this, we place the color patch strategically—either near the culet (bottom tip) or along the girdle—so that light reflects the full beauty of the gem. Inclusions are also carefully positioned to fall along the girdle, where they’re less visible.
Fact 2: The widest part of a gemstone is called the girdle.
Fact 3: The lower portion below the girdle is the pavilion.
Fact 4: The upper portion above the girdle is the crown.
We also choose the shape and cut at this stage—based on the natural crystal, color zones, and any internal inclusions. Unlike diamonds (which are often cubic), sapphires naturally form in elongated shapes—so oval and cushion cuts are more common than round.
To optimize sparkle and color, we cut sapphires at an angle of at least 39°, compared to 36° for diamonds.
During this process, the gem is preformed, and any non-durable inclusions are removed. For example, a rough sapphire that starts at 6 carats may reduce to 3.5 carats after preforming.
🔹 Step 3: Faceting & Polishing
In sapphire cutting, color comes first, brilliance second.
Fact 5: There are two main types of facets:
Brilliant facets (triangle-shaped) enhance sparkle.
Step facets (rectangular-shaped) enhance color.
Fact 6: The angle of the pavilion facets determines how much light returns to the eye—this is what makes the gem sparkle.
Fact 7: On average, a finished sapphire weighs only 25–30% of its original rough weight.
Step facets are usually placed on the pavilion of oval and cushion cuts to enhance color, while brilliant facets are used on the crown to boost brilliance. For darker sapphires, brilliant facets are sometimes added to the pavilion to increase liveliness.
Special cuts like radiant or scissor incorporate both types of facets for a perfect balance of brilliance and color.
Finally, the gemstone is polished using ultra-fine diamond dust on a copper plate. It takes immense care and expertise—even polishing requires specialists, as improper grit can leave marks.
Until polishing is complete, the gemstone’s true personality can’t be fully appreciated. A stone that started at 6 carats may finish at just over 2.2 carats after all steps are complete—but it will shine like a star.
💎 Every Gem Has a Story
Each sapphire we cut carries its own story—formed in the earth over millions of years, hand-cut with care, and now ready to become part of yours. At Nash Gems we go through the whole process getting the best gemstones to you.
👉 Shop our sapphire collection or get in touch to start your custom piece.
