How We Value Diamonds
A complete, transparent guide to the 4 Cs and everything else that determines your diamond’s worth.
The 4 Cs Explained
Carat measures weight, not size, one carat equals 200 milligrams, and larger stones are rarer and worth more per carat. Cut determines how well a diamond reflects light based on its proportions and facets. Color is graded from D (colorless) to Z (light yellow/brown); vivid “fancy color” diamonds are graded separately and can command real premiums. Clarity measures internal inclusions and surface blemishes.
How Much Does a GIA Certificate Matter?
A GIA certificate provides an independent, trusted assessment of a diamond’s exact grading, especially valuable for larger stones. We don’t require certification to evaluate or buy a diamond, but it typically speeds up the process and can support a stronger offer.
Other Factors That Affect Value
- Shape — round brilliant diamonds typically command a premium over fancy shapes.
- Fluorescence — UV glow that can slightly affect value depending on intensity and color grade.
- Market conditions — diamond prices shift with supply and demand like any commodity.
- Setting — the metal type and craftsmanship of a setting adds to a piece’s total value.
Ready to sell or borrow against your diamond? See our Sell Diamonds or Diamond Loans pages.
Frequently Asked Questions
What are the 4 Cs of diamond value?
Carat (weight), cut (how well it’s proportioned), color (how colorless it is), and clarity (how few visible inclusions it has).
Which of the 4 Cs matters most?
All four interact together, but generally cut has the biggest impact on visual brilliance, while carat weight has the biggest impact on price per stone.
Do I need a GIA certificate?
No, but it’s very helpful for larger diamonds since it provides an independent, trusted grading that can support a stronger offer.
Does the shape of my diamond affect its value?
Yes, round brilliant diamonds typically carry a premium over fancy shapes like princess, cushion, or emerald cuts.
What is fluorescence and does it matter?
Fluorescence is how a diamond glows under UV light. Depending on intensity and color grade, it can slightly increase or decrease value.
Can two diamonds of the same carat weight have very different values?
Yes, cut, color, and clarity can cause significant value differences even between diamonds of identical carat weight.