---
title: "Carat weight: why 2 ct isn't twice as big: lesson quiz"
description: "Five questions on “Carat weight: why 2 ct isn't twice as big”, lesson 2 of Digital Gemology's The four Cs course, in a new order every time, with an explanation for every answer."
url: https://digitalgemology.com/skool/quiz/the-four-cs/carat-weight
image: https://digitalgemology.com/img/og-digital-gemology.png?v=d224fb01
---

> Markdown copy of https://digitalgemology.com/skool/quiz/the-four-cs/carat-weight. 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

[The four Cs](https://digitalgemology.com/skool/quiz/the-four-cs#lessons) · lesson 2

# Carat weight: why 2 ct isn't twice as big

Lesson quiz · five questions, in a new order every time

Five questions on lesson 2 of The four Cs. The questions and the answers to pick from come in a new order every time you start.

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: A diamond weighs 0.40 ct. How many points is that?
  ### Show the answer
  **b**: The carat has 100 points.
2. Question 2: You double the carat weight of a diamond with the same cut. Its diameter grows by about:
  ### Show the answer
  **a**: The cube root of 2 is 1.26.
3. Question 3: In the [simulator](https://digitalgemology.com/tools/3d_gemstone_simulator) you step from 1 to 3 ct, and the stone stays the same size on screen. What changed?
  ### Show the answer
  **b**: The stone always fills the view; the scale bar and the report show the size.
4. Question 4: Why can two 1.00 ct diamonds face up at different sizes?
  ### Show the answer
  **b**: A deeper cut or a less dense material changes how much stone each carat buys.
5. Question 5: A friend can choose a 0.99 ct or a 1.00 ct stone of the same quality. What do you tell them?
  ### Show our answer
  The difference is 0.02 mm across, and nobody can see it. The 0.99 is usually the better buy.

## More

- Next: [Lesson 3, Color: D to Z](https://digitalgemology.com/skool/quiz/the-four-cs/color-d-to-z)
- [The The four Cs quiz](https://digitalgemology.com/skool/quiz/the-four-cs), on the whole course
- [All The four Cs lesson quizzes](https://digitalgemology.com/skool/quiz/the-four-cs#lessons)
- [The four Cs: all the lessons](https://digitalgemology.com/learn/four-cs)