How Diamonds Are Made: Cutting and Polishing a Diamond

When you step into a jewelry store and admire the sparkle of a diamond, you’re seeing the result of incredible skill and precision. Every diamond’s beauty is revealed through a careful process of cutting and polishing—steps that transform a rough stone into a brilliant gem.

From the Earth: Rough Diamonds

Diamonds begin their journey deep within the earth. When they’re first mined, they don’t resemble the dazzling gems you see in jewelry stores. In fact, rough diamonds often look dull, cloudy, and rock-like—which explains why diamonds are sometimes casually referred to as “rocks.”

Before any cutting begins, a skilled diamond cutter studies the rough stone carefully. They evaluate its shape, size, and natural inclusions (internal flaws) to determine how it can be cut to maximize beauty and value. Today, advanced computer imaging helps guide these decisions, although the cutter’s expertise remains essential.

Specialized tools—such as precision saws and lasers—are used to divide the rough diamond into workable pieces while minimizing waste and preserving weight.

Creating the Facets

Once the diamond is shaped, the cutter begins forming facets—the smooth, flat surfaces that cover the gem. These facets are critical to a diamond’s brilliance.

Facets allow light to:

• Enter the diamond

• Reflect internally

• Refract and disperse back out as sparkle

In round brilliant diamonds, the placement and number of facets are standardized to produce maximum fire and brilliance. Other diamond shapes use different facet patterns, which is why various cuts reflect light differently and produce unique visual effects.

The Final Step: Polishing

The last stage in the process is polishing. Even perfectly cut facets won’t shine without a smooth finish. Using specialized equipment and ultra-fine abrasives, the cutter polishes each facet to a mirror-like surface.

The smoother the facets, the more effectively the diamond reflects and disperses light—resulting in the sparkle diamonds are famous for.

Appreciating the Craft

Every diamond represents hours of expert craftsmanship, precision, and careful decision-making. From a rough stone hidden beneath layers of earth to a radiant gem that catches every beam of light, the cutting and polishing process is what unlocks a diamond’s true beauty.

The next time a diamond catches your eye, you’ll know just how much skill went into making it shine.