# Ruby Red (DD-167)

> 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.

- Department: Science (also Nature)
- First published: 2024-01-07
- Last updated: 2024-01-07
- Permalink: https://detailenjoyer.com/case/ruby-red/
- Author: Marcus Easterling (DetailEnjoyer), The Detail Department

## Quick facts

- **DD-167-F01**: Ruby is a red variety of corundum. _(Write-up · Exhibit A (Corundum))_
- **DD-167-F02**: Chromium gives ruby its red color. _(Write-up · Exhibit B (Chromium))_

## Write-up

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

1. **Corundum**: Ruby is a red variety of corundum.
2. **Chromium**: Chromium gives ruby its red color.
3. **Sapphire**: Other colors of corundum are called sapphire.
4. **Color sets value**: Color is the main factor in value.
5. **Mohs 9**: Ruby rates 9 on the Mohs scale.

## Related case files

- [No Perfect Crystallizations (DD-288)](https://detailenjoyer.com/case/no-perfect-crystallizations/): I linked more about how crystals form
- [Exceptionally Emerald! (DD-170)](https://detailenjoyer.com/case/exceptionally-emerald/): I paired it with another chromium-colored gem
- [Shine Bright (DD-165)](https://detailenjoyer.com/case/shine-bright/): I linked more gems
- [Azure Asterism (DD-166)](https://detailenjoyer.com/case/azure-asterism/): I linked ruby, the red form of corundum
- [Quartz Crystals (DD-168)](https://detailenjoyer.com/case/quartz-crystals/): I linked another crystal prized for its structure

## Reel vs. record

- **Note**: None needed. 'Mystical properties' is belief, not fact; I kept it attributed to cultures.

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

- Duration: 28.0 s · Published: 2024-01-07
- File: https://detailenjoyer.com/assets/videos/C10XXFhpJK6.mp4

### Transcript

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!

## Questions & answers

**Q: What mineral is ruby?**  
A: Aluminum oxide. _(Source: Write-up · Exhibit A (Corundum) · Wikipedia: Ruby)_

**Q: What gives ruby its red?**  
A: Trace amounts. _(Source: Write-up · Exhibit B (Chromium) · Wikipedia: Ruby)_

**Q: What is non-red corundum called?**  
A: Blue is the classic color. _(Source: Write-up · Exhibit C (Sapphire) · Wikipedia: Ruby)_

**Q: What matters most for value?**  
A: Deep red is prized. _(Source: Write-up · Exhibit D (Color sets value) · Wikipedia: Ruby)_

**Q: How hard is ruby?**  
A: Only diamond is harder among common gems. _(Source: Write-up · Exhibit E (Mohs 9) · Wikipedia: Ruby)_

## Sources

- [Wikipedia: Ruby](https://en.wikipedia.org/wiki/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/