CDG Study Guide 2026
Everything you need to pass the CDG exam in one place: the exam format, every topic to study, real practice questions with explanations, flashcards, and full-length practice tests. Free, no sign-up needed.
📋 CDG Exam Format at a Glance
📚 CDG Topics to Study (21)
✍️ Sample CDG Questions & Answers
1. Between which clarity grades is the price difference per grade typically most dramatic?
The FL to IF distinction commands one of the largest per-grade price jumps because flawless diamonds are extremely rare and highly sought after by premium buyers.
2. How does KM (Kiduah Meyuchad) drilling differ from traditional laser drilling?
KM drilling creates a surface-reaching fracture that reaches the inclusion without leaving a straight drill hole, making it harder to detect than traditional laser drilling.
3. What substance is most commonly used in fracture filling of diamonds?
Lead glass is the most common fracture-filling material because its refractive index closely matches that of diamond, making the filled fractures nearly invisible.
4. Which method is commonly used for root cause analysis in CDG quality management?
Structured root cause analysis methods like Five Whys and fishbone diagrams systematically trace problems to their fundamental causes rather than symptoms.
5. What is the role of internal audits in Certified Diamond Grader compliance management?
Internal audits proactively verify compliance, identify gaps, and drive improvement before external inspections or incidents reveal problems.
6. How should an CDG professional present complex findings to non-experts?
Complex information should be translated into accessible language with visual aids, followed by checking for understanding to ensure effective communication.