One of the most useful tools in evaluating rough gemstones—especially online—is the White Paper Test. While it may seem like a basic setup, presenting rough on a clean white background allows buyers to assess color and saturation more clearly, without distraction or visual distortion.

This approach offers a standardized, repeatable way to judge cutting potential when the buyer cannot inspect the stone in person.

What Is the White Paper Test?

The White Paper Test (WPT) involves placing the rough gemstone on plain white paper under neutral lighting. It avoids color reflections from trays, hands, or backgrounds, making it easier to judge:

• Is the stone dark, lifeless, or overly saturated?

• Is the color concentrated or washed out?

• Does the stone have potential for a bright, open cut?

Over time, buyers and dealers alike have come to rely on this test for online evaluations.

Limitations of the White Paper Test

Like all tools, the White Paper Test is helpful but imperfect. It can’t reveal everything—especially when the rough has a thick skin. 

White paper  (or in the above example, a shinny white plastic tray) near a bright light source can reflect light through the stone, making it appear more open than it actually is.

Window light is intense and focused. It can artificially brighten dark stones, giving a false impression of saturation.

Reflective metal trays bounce light through the bottom of the stone. These photos can look appealing—but often mislead. Always be cautious of a piece of rough only shown on a reflective surface

Placing a flashlight under a stone in a plastic bag creates a glow that won’t appear in normal viewing or cutting. Notice the true color of these roughs are on the left side of the photo 

These techniques can make rough look brighter, cleaner, or more colorful than it is—especially in online listings.

Why the White Paper Test Remains Valuable

Despite its limitations, the White Paper Test provides a more neutral and honest baseline for evaluating rough. It shows the piece without added color influence, helps reveal true saturation, and is easily repeatable in any lighting environment. When used ethically and consistently, it supports transparency between seller and buyer.

Conclusion

The White Paper Test won’t tell you everything about a piece of rough—but it will give you a cleaner, more reliable view than many of the alternatives. For online gem buyers, it’s one of the simplest ways to judge a stone’s true color and potential before placing a bid.