CGA Study Guide 2026
Everything you need to pass the CGA 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.
📋 CGA Exam Format at a Glance
📚 CGA Topics to Study (21)
✍️ Sample CGA Questions & Answers
1. On the GIA diamond color scale, which grade represents a colorless diamond?
The GIA color scale begins at D (colorless) and runs through Z (light yellow or brown), with D being the highest and rarest color grade.
2. A CGA certified professional is asked to provide services outside their scope of competence. The CORRECT ethical response is to:
Ethical practice requires professionals to work within their scope of competence.
3. A CGA appraiser who knowingly fails to disclose a significant gemstone treatment in a written appraisal report is most directly in violation of:
USPAP (Uniform Standards of Professional Appraisal Practice) requires appraisers to report all known factors that materially affect value; omitting a treatment disclosure violates USPAP ethics rules and the ASA/AGS codes of professional conduct.
4. A CGA appraiser examines a diamond and finds it has an 'SI1' clarity grade. What does this mean?
SI1 (Slightly Included 1) diamonds have noticeable inclusions that are easy to see under 10x magnification but are typically not visible to the unaided eye.
5. Which of the following best describes a narrative appraisal report?
A narrative appraisal report is a detailed, written document that fully explains the appraiser's findings, analysis, and conclusions. It includes extensive descriptions, market research, and a thorough justification for the determined value, often presented in a prose format. This comprehensive approach provides the most in-depth understanding of the valuation process.
6. For a CGA appraisal, what does 'treatment disclosure' mean for colored gemstones?
Treatment disclosure requires appraisers to identify and disclose any enhancements (e.g., heat treatment, fracture filling, irradiation) that have altered the gemstone's natural appearance, color, or durability.