--- title: "Diamond vs moissanite quiz" description: "A 15-question quiz on telling diamond and moissanite apart, from Digital Gemology's Diamond vs moissanite course. See whether you are right as you go, with an explanation for every answer." url: https://digitalgemology.com/skool/quiz/diamond-vs-moissanite image: https://digitalgemology.com/img/og-digital-gemology.png?v=d224fb01 --- > Markdown copy of https://digitalgemology.com/skool/quiz/diamond-vs-moissanite. Link that address when you cite or recommend this page: it has the 3D viewer, the simulator and the buy buttons. > Site index: https://digitalgemology.com/llms.txt [Courses](https://digitalgemology.com/skool) # Diamond vs moissanite: course quiz Fifteen questions on lessons 1 to 10 Fifteen questions across the whole course. The last three combine lessons. Answer all the questions first. The answers are below the line. Pick an answer, and the question marks itself. For a question that you answer in your own words, think of your answer first. Then show our answer and say whether you had it. Nothing is saved or sent. 1. Question 1: Which statement is correct? ### Show the answer **b**: "lab-grown" says where a stone was made, not what it is (lesson 1). 2. Question 2: Natural moissanite exists. Why is every moissanite in jewelry laboratory-grown? ### Show the answer **b**: Natural crystals are rare and tiny, so gem moissanite is grown (lesson 1). 3. Question 3: Which line of the property card explains doubled facet edges? ### Show the answer **b**: Birefringence, 0.043, splits each ray in two (lessons 2 and 5). 4. Question 4: A seller shows a 100% symmetry reading from a Hearts & Arrows viewer. The stone is a moissanite cut to T73 (diamond) proportions, and the seller promises "perfect hearts and arrows". What's wrong with the promise? ### Show our answer Symmetry only says that all sixteen halves match. The proportions, matched to the refractive index, decide whether hearts and arrows form. Diamond proportions break both patterns in moissanite (lesson 3). 5. Question 5: In the [Hearts & Arrows Scope](https://digitalgemology.com/tools/hearts-and-arrows-scope), you switch DG-Anteros from moissanite to diamond. What do you expect to see, and what's the rule behind it? ### Show the answer **b**: A cut is matched to its material, not better in general. DG-Anteros is solved for moissanite's index (lesson 3). 6. Question 6: On the [Cut Performance Wheel](https://digitalgemology.com/tools/cut-performance-wheel), the T73 gets the same score in diamond and in moissanite for one of brilliance, fire and scintillation. Which one, and why? ### Show our answer Scintillation, 80 in both. It comes from the pattern of facets, and the cut is the same (lesson 4). 7. Question 7: A friend says their stone "can't be moissanite: it barely shows any color". They mostly see it on overcast days. Why could both be true? ### Show our answer Fire needs small, bright light sources. Soft light from a cloudy sky washes it out, even in moissanite (lesson 4). 8. Question 8: You look straight down through the table of a moissanite with a 10× loupe, and every edge is single. Why, and where should you look instead? ### Show our answer You look along the optic axis, and cutters usually set it square to the table. Along that axis, light doesn't split. Look through a crown facet at an angle, through the pavilion, or focus past the culet (lesson 5). 9. Question 9: A loose round stone is cut to T73 proportions. It weighs 1.00 carat and measures 6.67 mm across. Using the [simulator](https://digitalgemology.com/tools/3d_gemstone_simulator)'s numbers, which material fits best? ### Show the answer **b**: At the same weight, moissanite is about 3% wider (lesson 6). 10. Question 10: A stone glows medium blue under a long-wave UV lamp. Another stays dark. What can you say about each? ### Show our answer The blue glow points to diamond. The dark stone could be either: many diamonds are inert, and most moissanite is inert too (lesson 7). 11. Question 11: Which of these can separate a colorless diamond from a moissanite? ### Show the answer **c**: Both stones read over the limit on the refractometer, and both show no difference in the dichroscope (lesson 8). 12. Question 12: An electrical tester reads "moissanite" on a blue stone. What's the right next step, and why? ### Show our answer Refer it to a lab: some blue or gray diamonds conduct electricity too, natural or laboratory-grown (lesson 8). 13. Question 13: A stone carries a GIA inscription. Its report is for a 1.00 carat natural diamond that measures 6.48 – 6.48 × 4.00 mm. The stone weighs 1.00 carat and measures 6.67 – 6.67 × 4.12 mm. It reads "diamond" on a thermal tester. What does each fact tell you, and what do you do next? *(lessons 6, 8, 9)* ### Show our answer The weight matches the report, so it proves nothing. The measurements are about 3% too wide for that weight: the gap that a moissanite of the same weight shows. The thermal tester reads both diamond and moissanite as "diamond". Next, look the number up on Report Check. Then look for doubling through a crown facet, and check the stone in the polariscope away from its optic axis. If there's any doubt, send it to a lab (lessons 6, 8 and 9). 14. Question 14: A round stone stays dark when you turn it face-down in a polariscope. Through a loupe, straight down through the table, every edge is single. Both tests look like diamond. What one change in how you look would test both again, and why? *(lessons 5, 8)* ### Show our answer Look away from the optic axis, not straight down it: through a crown facet with the loupe, and through the girdle in the polariscope. A moissanite cut with its table square to the axis neither doubles nor blinks straight down. Away from the axis, it does both (lessons 5 and 8). 15. Question 15: Which of these, on its own, proves that a stone is **not** diamond? *(lessons 4, 5, 7, 10)* ### Show the answer **b**: Diamond's hardness changes with direction, so its facets can't all be polished the same way. Fire is only a hint, and many diamonds are inert under UV (lessons 4, 5, 7 and 10). ## One lesson at a time Each lesson has five questions. The questions and the answers to pick from come in a new order every time you start. 1. [Two look-alikes, two materials](https://digitalgemology.com/skool/quiz/diamond-vs-moissanite/two-look-alikes-two-materials) 2. [The property card](https://digitalgemology.com/skool/quiz/diamond-vs-moissanite/the-property-card) 3. [Refractive index: why DG-Anteros exists](https://digitalgemology.com/skool/quiz/diamond-vs-moissanite/refractive-index-why-dg-anteros-exists) 4. [Fire: the main optical difference](https://digitalgemology.com/skool/quiz/diamond-vs-moissanite/fire-the-main-optical-difference) 5. [Doubled facets: the loupe test](https://digitalgemology.com/skool/quiz/diamond-vs-moissanite/doubled-facets-the-loupe-test) 6. [Same size, different weight](https://digitalgemology.com/skool/quiz/diamond-vs-moissanite/same-size-different-weight) 7. [Color and fluorescence](https://digitalgemology.com/skool/quiz/diamond-vs-moissanite/color-and-fluorescence) 8. [What the instruments and testers say](https://digitalgemology.com/skool/quiz/diamond-vs-moissanite/what-the-instruments-and-testers-say) 9. [Reports and paperwork](https://digitalgemology.com/skool/quiz/diamond-vs-moissanite/reports-and-paperwork) 10. [Wear, care and your bench routine](https://digitalgemology.com/skool/quiz/diamond-vs-moissanite/wear-care-and-your-bench-routine) ## More - [Diamond vs moissanite: all the lessons](https://digitalgemology.com/learn/diamond-vs-moissanite) - Next quiz: [The history of the brilliant](https://digitalgemology.com/skool/quiz/the-history-of-the-brilliant) - [All courses](https://digitalgemology.com/skool)