
The brilliance, fire, and clarity of a diamond captivate like no other gemstone. But with its allure comes the worry: Is a diamond truly genuine? Whether you’re investing in an engagement ring, heirloom piece, or a dazzling pair of earrings, understanding how to verify diamond authenticity is essential. At Koerber’s Fine Jewelry, we believe knowledge empowers you to make confident choices, protect your investment, and appreciate beauty with assurance. So, let’s remove the mystery and help you shop smart!

Why Authenticity Matters
A real diamond holds not just aesthetic appeal but lasting value. A genuine stone retains resale potential, heritage, and emotional significance. A fake or misrepresented piece can risk disappointment, financial loss, and distrust. Checking authenticity ensures your jewelry lives up to its promise and allows you to wear it with confidence rather than concern.
Moreover, as technology evolves, counterfeiters attempt ever more convincing imitations. Tools that once were available only to experts are now more accessible. Understanding basic tests and trusting trained professionals helps you separate sparkle from deception.
Common Indicators of a Real Diamond
1. The Fog Test (Breath Test)
Hold the diamond close to your mouth and breathe on it, as if fogging a mirror. A real diamond disperses heat quickly, so the fog should clear almost immediately. If it lingers for several seconds, it may not be genuine.
2. The Water Test
A real diamond’s density is high. Place it in a glass of water. A genuine diamond will sink; many fakes will float or sink slowly. Though simple, this test is not foolproof, especially for small stones in heavy settings.
3. Magnification and Inclusions
Under a jeweler’s loupe (10× magnification), examine the stone’s internal features. Natural diamonds usually contain minor inclusions or imperfections (tiny crystals, feathers, or graining). A perfectly flawless stone might be suspect, either because it is extremely rare or because it is synthetic.
4. Refraction & Light Behavior
Diamonds have a high refractive index, bending light sharply and creating bright sparkles. If you can see distinct reading lines or text through the stone when held over printed material, it may not be a genuine diamond, as imitations often allow more light to pass through.
5. Check the Mount & Setting
Often, counterfeit stones are set in low-quality settings, thin prongs, poor metal, or glue. If the mounting seems flimsy, it raises suspicion. A real diamond in a well-made setting suggests the jeweler values the integrity of the piece.
Lab-Grown Diamonds vs Mined Diamonds
Today’s technology allows diamonds to be grown in labs under controlled conditions. These lab-grown diamonds share the same chemical and physical structure as mined diamonds: they sparkle, cut the same, and pass many authenticity tests. Yet they differ in origin, rarity, and, often, price.
Key differences:
- Origin: Lab-grown diamonds are artificially produced; mined diamonds come from Earth’s natural processes.
- Cost: Lab-grown diamonds often cost less per carat, sometimes 20 – 40% lower than comparable mined stones.
- Resale & Perception: Mined diamonds tend to hold traditional prestige and resale value. Lab-grown diamond resale markets are evolving.
- Sustainability: For some buyers, lab-grown diamonds offer a more ethical or environmentally conscious choice.
Common Myths & Misconceptions
- “Diamonds are always clear or colorless.” In fact, many natural diamonds carry light colors or hues, tints of yellow or brown, especially in desirable fancy colors.
- “All real diamonds sparkle intensely.” The sparkle (brilliance + fire) depends heavily on the cut. A poor cut reduces sparkle regardless of stone authenticity.
- “Fake diamonds always look fake.” Some simulants and synthetics are extremely convincing under casual observation. That’s why tests and certificates matter.
- “If it’s big, it’s fake.” Large diamonds exist but are rare. A large piece demands extra scrutiny, particularly for clarity and certification, but size alone isn’t proof.
Find Your Perfect Diamond at Koerber’s
At Koerber’s Fine Jewelry, we adhere to strict standards: every diamond in our collection is vetted, documented, and backed by our assurance of quality. When you choose us, you choose peace of mind: genuine diamonds, transparent information, and long-term care. Visit our showroom or browse online to experience true diamond brilliance, backed by authenticity you can trust!