Last Updated: April 2026
TL;DR:
- No — only about 0.5% of diamonds are Internally Flawless. The rest, including yours, almost certainly have inclusions, and black carbon spots are one of the most common types.
- A black spot doesn’t ruin a diamond. SI1 and SI2 clarity stones with small dark inclusions can sell for 15-30% less than VS-grade diamonds with the same color and cut.
- Laser-drilled diamonds treated to remove black spots typically sell for 30-60% less than untreated stones of the same clarity — always ask if a diamond has been treated before you buy.
Diamonds are marketed as flawless, sparkling, forever stones. In reality, most of them carry tiny internal marks called inclusions, and black carbon spots are among the most common. If you’ve spotted a dark fleck in a diamond you’re considering — or already own — you’re not looking at a defect in the traditional sense. You’re looking at how the stone actually formed a billion years ago. This guide breaks down what causes black spots, whether they lower value, and what you can do about them. For a deeper technical breakdown, see our guide on what an inclusion in a diamond actually is.
Is It Common for a Diamond to Develop a New Black Spot?
No. A diamond you already own will not develop a new black spot over time. Carbon inclusions form only during crystallization, roughly 90 to 125 miles underground, under conditions of extreme heat and pressure that no longer exist once the stone is cut and set. What you see is what was always there.
I’ve had customers bring in rings convinced a spot “appeared” after a few years of wear. It didn’t — it was there at purchase, just harder to notice under office lighting than under a jeweler’s loupe. Diamonds form entirely from carbon atoms bonding into a crystalline lattice. When the process is clean, you get a colorless, high-clarity stone. When gases, minerals, or unconverted carbon get trapped mid-formation, you get inclusions — and trapped carbon that never crystallized reads as a black spot under magnification.
According to GIA, clarity graders evaluate the size, position, color, and quantity of these characteristics under 10x magnification — the same standard used for every certified stone worldwide. Nothing about that grade changes after the diamond leaves the lab.
Do All Diamonds Have Black Spots?
No. Not every diamond has black spots, but very few diamonds are completely inclusion-free. Only around 0.5% of natural diamonds grade as Internally Flawless. The rest fall somewhere on the clarity scale, and a portion of those specifically carry visible carbon inclusions rather than clouds, feathers, or crystals.
The diamond formation process happens over a billion years in an environment nobody controls. That’s exactly why perfection is rare and expensive. Most stones you’ll actually shop for — SI1, SI2, VS1, VS2 — carry some inclusion, whether that’s a black carbon spot, a white crystal, or a feather. Our post on whether cloudy diamonds hold any value covers a related issue — hazy, milky stones caused by clusters of pinpoint inclusions rather than a single dark spot.
Is It Worth Buying a Diamond With a Black Spot?
Yes, if the spot is small and graded SI1 or better — no, if it’s large, central, or graded I1/I2/I3. A heavily included stone loses sparkle because the dark material blocks light return, and enough carbon inclusions can weaken the diamond’s structure to the point it chips more easily under pressure.
An SI1 or SI2 diamond with a small, edge-positioned black spot is often invisible to the naked eye and can cost noticeably less than a VS-clarity equivalent — a legitimate way to stretch a budget. What I tell customers to avoid is anything graded I1 or lower with a spot near the center or table of the stone — those show up under normal room lighting and, in worse cases, create a weak point in the crystal. Read our breakdown on whether diamonds with black spots actually sell cheaper for pricing specifics by clarity tier. If price is the main driver, it’s also worth comparing moissanite engagement ring options, since simulants never carry natural carbon inclusions the way mined diamonds do.
Can You Remove a Black Spot From a Diamond?
1. Laser Drilling and Fracture Filling
A technician drills a microscopic channel — thinner than a human hair — directly into the diamond to reach the black inclusion, then applies heat or acid to burn or dissolve the carbon. The resulting hollow is filled with a glass-like compound through fracture filling to restore the diamond’s apparent clarity.
This isn’t risk-free. Drilling a heavily included stone can weaken it further, and fracture-filled diamonds are vulnerable to ultrasonic cleaners and high heat — a jeweler’s torch can boil out the filler. Treated stones also carry a real resale penalty: DiamondRensu notes laser-drilled, GIA-graded diamonds typically sell for 30-60% less than untreated stones of comparable clarity. Always ask for disclosure — reputable sellers list “laser drilled” or “fracture filled” on the certificate.
2. Choose a Setting That Hides the Spot
Prong and bezel settings can mask a black spot depending on where it sits in the stone. Neither works if the inclusion is dead center or near the table — there’s no metal to hide behind there. For inclusions closer to the girdle, a jeweler can often rotate the stone during setting so the spot faces the shank instead of straight up.
3. Keep the Diamond Clean
Dust and skin oil make small black spots look bigger and darker than they are, especially on stud earrings and rings worn daily. This won’t fix a large inclusion, but for a tiny, barely-visible spot, a weekly clean with warm water, a drop of dish soap, and a soft toothbrush keeps it from standing out. If you’re dealing with buildup instead of an actual inclusion, check our guide on whether diamonds can get scratched before reaching for anything abrasive.
4. Upgrade Clarity Instead of Treating the Stone
If a visible black spot bothers you, the more durable fix is buying up in clarity rather than treating what you have. Moving from I1 to SI1 removes most obvious carbon spots without the resale hit of a laser-drilled stone. Going further to VS1, VVS1, or VVS2 (Very Slightly Included, Very Very Slightly Included) all but eliminates visible inclusions — Internally Flawless stones exist but carry a steep premium. Our piece on what “clarity enhanced” actually means on a certificate is worth reading first, since some “enhanced” stones are treated rather than naturally higher-clarity.
Why Do Some Diamonds Cost So Much Less Than Others With the Same Carat?
Clarity is one of four factors — along with cut, color, and carat — that set a diamond’s price, and inclusions like black spots are the biggest clarity-driven discount lever. Two one-carat diamonds can differ by hundreds or thousands of dollars purely because one has visible carbon spots and the other doesn’t.
According to The Knot, most shoppers can’t see the difference between VS2 and SI1 with the naked eye, which makes SI1 one of the better value grades for anyone not chasing a certificate number. Our guide on why diamonds cost what they cost breaks down all four Cs together.
The Bottom Line
Black spots are carbon that never finished crystallizing, locked into the diamond a billion years before it ever reached a ring. They’re common, they’re permanent once formed, and in small sizes at the edge of a stone, they’re often invisible without a loupe. Don’t pay VS prices for an I1 diamond with a visible dark spot dead center — but don’t walk away from a well-priced SI1 either, since clarity treatments don’t always hold up long-term and an untreated natural inclusion never will fail on you. Check the certificate, ask about treatment, and buy the clarity grade that matches what your eye — not the price tag — tells you.
Frequently Asked Questions
What causes black spots inside a diamond?
Black spots are pockets of carbon that were trapped inside the diamond during crystallization but never fully converted into the crystal structure. They form 90 to 125 miles below the earth’s surface under extreme heat and pressure, long before the stone is ever cut.
Do black spots mean a diamond is fake?
No. Black carbon inclusions are actually a sign of a natural diamond’s authentic, uncontrolled formation process. Lab-grown diamonds and simulants like moissanite or cubic zirconia typically don’t show this specific type of natural carbon inclusion.
What clarity grade should I buy to avoid visible black spots?
SI1 or higher is a safe floor for most shoppers, since inclusions at that grade are usually only visible under magnification. If you want zero risk of any visible mark, go VS2 or higher.
Does laser drilling permanently remove a black spot?
The visible spot is gone, but the treatment must be disclosed on the certificate, and the filled channel can be damaged by ultrasonic cleaning or high heat from jewelry repair torches, which can make the spot reappear or the filler cloud over.
Will a black spot get worse over time?
No. Carbon inclusions are fixed at formation and don’t grow, spread, or change after the diamond is cut and set. If a spot looks different, it’s almost always dirt or oil buildup, not the inclusion itself changing.
Can a jeweler tell if a black spot will make my diamond crack?
Yes, under magnification. A single small inclusion rarely poses a risk, but multiple inclusions clustered near the girdle or culet can create a weak point worth flagging before you set the stone.
Tiger is a fashion&jewelry lover. He is also a fashion jewelry manufacturer that help thousands of small business to grow and also do business with some big fashion jewelry brands. He is a truly metal expert and he will share some information you are looking for.