Gemstone Value Calculator
Estimate the value of any gemstone based on type, carat weight, quality grade, and treatment status.
Quick Gemstone Valuation
Get an estimated value range for your gemstone.
Per-Carat Price Estimator
See estimated per-carat prices across gemstone types and quality levels.
Treatment Impact on Value
See how different treatments affect gemstone value.
Formula
Price increases exponentially with carat weight for rare stones
Frequently Asked Questions
How is gemstone value determined?
Which gemstones are most valuable?
Do gemstones hold their value?
Understanding Gemstone Value
Gemstone valuation is both an art and a science. Unlike diamonds, which have standardized pricing through the Rapaport system, colored gemstones are evaluated subjectively by experts. The most important factor is color -- the ideal color varies by gemstone type. For rubies, a vivid "pigeon blood" red is most prized; for sapphires, a medium-dark "cornflower" blue; for emeralds, a vivid green with slight blue secondary hue.
Treatment status dramatically impacts value. Heat treatment of rubies and sapphires is widely accepted and may only reduce value by 10-30% compared to untreated stones. However, fracture filling, diffusion, or lead-glass filling can reduce value by 80-95%. Always request a gemological laboratory report from GIA, GRS, or Gubelin when purchasing or valuing high-end gemstones.
Carat weight follows a non-linear pricing curve for rare gemstones. A 3-carat fine ruby doesn't cost 3x a 1-carat ruby -- it may cost 5-10x more because large fine rubies are exponentially rarer. This "per-carat premium" effect is strongest for rubies, sapphires, emeralds, and alexandrites.