Valuation – Main Lesson

Unit 11: How Much is a Gem Worth?

What’s This All About? 

The big question! Jake teaches us the famous “Four Cs” system that gemologists worldwide use to determine how valuable any gemstone really is.

Key Takeaways: 

• The Four Cs System: Color, Clarity, Cut, and Carat Weight work together to determine final value 
• Color (most important factor for colored gems):
  • Hue: The basic color family (red, blue, green, yellow, purple, orange, etc.)
  • Tone: How light or dark the color appears (from very light to very dark)
  • Saturation: How pure and intense the color is (from grayish/brownish to vivid)
  • Generally, more vivid and pure colors are more valuable
  • Example: Deep, rich blue sapphire is worth more than pale, washed-out blue 
• Clarity (freedom from inclusions and blemishes):
  • Fewer inclusions typically means higher value and greater rarity
  • Important exception: Different gem types have different clarity expectations
  • Emeralds are expected to have inclusions (called “jardin”)
  • Aquamarines are expected to be much cleaner with fewer visible inclusions
  • Surface blemishes vs. internal inclusions are evaluated differently 
• Cut (precision of faceting and proportions):
  • Not just about shape, but how well the angles and proportions are executed
  • Think of faceted gems as surrounded by mirrors inside

International Gem Society

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