Lesson 37 · Gemstones & Earrings · 31 seconds
Sapphire is not always blue
Sapphire is a variety of the mineral corundum, and it comes in many colors: blue, pink, yellow, orange, green, purple and even colorless. When corundum is red, it is called ruby. Color alone cannot tell you what a stone is, where it is from or whether it was treated; that takes a gemological lab report.
What this lesson shows
One mineral, many colors.
A row of loose sapphires in seven colors and a red ruby lead into a simplified diagram of the corundum family. The lesson closes on a loupe beside a pink stone held in tweezers.
Three quick takeaways
What to actually do when you shop
- Sapphire is a variety of corundum, and it comes in many colors: blue, pink, yellow, orange, green, purple, even colorless. Red corundum is called ruby.
- Color alone cannot tell you what a stone is, where it is from or whether it was treated. That takes a gemological lab report.
- Judge a colored stone by its lab report, not by its color alone.
Read the transcript
Which of these is sapphire? More than you think. Sapphire is a variety of corundum, and it comes in many colors: blue, pink, yellow, orange, green, purple, even colorless. When corundum is red, it's called ruby. So color alone can't tell you what a stone is, where it's from, or whether it was treated. That takes a gemological lab report. Explore more in the Aydins Jewelry Learning Center.
Sources
- GIA, sapphire description: www.gia.edu/sapphire-description
- GIA, sapphire quality factors: www.gia.edu/sapphire-quality-factor
- GIA, sapphire buyer's guide: www.gia.edu/sapphire/buyers-guide
- GIA, gem treatments: www.gia.edu/gem-treatment
Related lessons
Why opal changes color when you tilt it · play-of-color in precious opal.
Same diamond, three lights · how light changes what you see.
Three checks before trusting a diamond report · how to read and match a report.
Next step
Browse rings with precious stones.
Read each ring's stone details before you compare.