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Ruby Red

Short answer: Ruby is the red gem variety of corundum, crystalline aluminum oxide. Its color comes from small amounts of chromium; corundum in other colors is called sapphire.

Color is the most important factor in a ruby's value, with a deep, vivid red (often called 'pigeon's blood') prized most. Rubies rate 9 on the Mohs hardness scale, behind only diamond among common gems. Rubies have long carried cultural meanings of passion and protection in many traditions. The footage shows cut and rough rubies, with the presenter.

VideoWrite-up1 sources
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What should you know about Ruby Red?

Quick facts. Each one stands alone and has a stable ID you can cite.

  1. Ruby is a red variety of corundum.

    DD-167-F01 · Write-up · Exhibit A (Corundum)

  2. Chromium gives ruby its red color.

    DD-167-F02 · Write-up · Exhibit B (Chromium)

Video transcript: Ruby Red: A Trace of Chromium Makes Corundum a Ruby

Rubies part of the corundum family are distinguished by their rich red color ranging from pinkish to blood red. DID YOU KNOW? The intensity of the red hue is a crucial factor in determining the quality and value of in various cultures, rubies have been associated with passion, protection, and prosperity. They are believed to possess mystical properties symbolizing love and vitality. Rubies are not only sought after in jewelry but also hold cultural significance making them prize gemstones in the world of gemology NOW YOU KNOW!

Burned-in captions, read frame by frame (see transcript.md) · 28.0s Reel ·

Video coming soonRuby Red · Instagram Reel
Ruby Red: A Trace of Chromium Makes Corundum a Ruby Instagram Reel · · 28.0s

The write-up

A trace of chromium makes corundum a ruby. Without the red, the same mineral is called sapphire.

  1. Exhibit A

    Corundum

    Ruby is a red variety of corundum.

  2. Exhibit B

    Chromium

    Chromium gives ruby its red color.

  3. Exhibit C

    Sapphire

    Other colors of corundum are called sapphire.

  4. Exhibit D

    Color sets value

    Color is the main factor in value.

  5. Exhibit E

    Mohs 9

    Ruby rates 9 on the Mohs scale.

Questions people ask about Ruby Red

What mineral is ruby?

Aluminum oxide.

Source: Write-up · Exhibit A (Corundum) · Wikipedia: Ruby

What gives ruby its red?

Trace amounts.

Source: Write-up · Exhibit B (Chromium) · Wikipedia: Ruby

What is non-red corundum called?

Blue is the classic color.

Source: Write-up · Exhibit C (Sapphire) · Wikipedia: Ruby

What matters most for value?

Deep red is prized.

Source: Write-up · Exhibit D (Color sets value) · Wikipedia: Ruby

How hard is ruby?

Only diamond is harder among common gems.

Source: Write-up · Exhibit E (Mohs 9) · Wikipedia: Ruby

Test Your Knowledge

All quizzes →

5 questions, all from this case file. Answers are revealed instantly.

  1. What mineral is ruby?

    1. Corundum
    2. Quartz
    3. Beryl
    4. Feldspar
    Show the answer

    Answer: A. Corundum Aluminum oxide. Source: Write-up · Exhibit A (Corundum) · Wikipedia: Ruby

  2. What gives ruby its red?

    1. Chromium
    2. Iron only
    3. Copper
    4. Carbon
    Show the answer

    Answer: A. Chromium Trace amounts. Source: Write-up · Exhibit B (Chromium) · Wikipedia: Ruby

  3. What is non-red corundum called?

    1. Sapphire
    2. Emerald
    3. Topaz
    4. Opal
    Show the answer

    Answer: A. Sapphire Blue is the classic color. Source: Write-up · Exhibit C (Sapphire) · Wikipedia: Ruby

  4. What matters most for value?

    1. Color
    2. Weight only
    3. Shape
    4. Age
    Show the answer

    Answer: A. Color Deep red is prized. Source: Write-up · Exhibit D (Color sets value) · Wikipedia: Ruby

  5. How hard is ruby?

    1. 9 on Mohs
    2. 5 on Mohs
    3. 2 on Mohs
    4. 10 on Mohs
    Show the answer

    Answer: A. 9 on Mohs Only diamond is harder among common gems. Source: Write-up · Exhibit E (Mohs 9) · Wikipedia: Ruby

Cite this case file

Easterling, Marcus. "Ruby Red." The Detail Department (DetailEnjoyer), case file DD-167, last updated Jan 7, 2024. https://detailenjoyer.com/case/ruby-red/

Permalink: https://detailenjoyer.com/case/ruby-red/ · Last updated

Markdown version

Cite a single fact by its ID, for example DD-167-F01 → https://detailenjoyer.com/case/ruby-red/#DD-167-F01