A dated survey of Amazon listings
Lab vs mined gem prices per carat
On October 17, 2026, the median loose lab-grown sapphire in our Amazon catalogue cost about $7.92 a carat, while mined sapphire sold with a lab report cost about $2,250 a carat (43 and 87 listings), about 280 times as much. Lab ruby came to about $7.80 a carat against about $940 for mined ruby (35 and 48 listings), so in these listings the same mineral cost about 120 times as much when it came out of the ground.
Checked in stock on , 334 listings (154 lab-grown, 180 mined).
Amazon prices as of . Prices and availability are accurate as of that date and time and are subject to change; the price shown on Amazon at the time of purchase applies.
At a glance
| Gem | Lab-grown | Mined | Mined vs lab | Listings (lab / mined) |
|---|---|---|---|---|
| Sapphire | $7.92 / ct | $2,250 / ct | about 280 times as much | 43 / 87 |
| Ruby | $7.80 / ct | $940 / ct | about 120 times as much | 35 / 48 |
| Emerald | $59 / ct | Too few | Not compared | 55 / 1 |
| Alexandrite | $56 / ct | Too few | Not compared | 21 / 2 |
A median needs at least 5 listings with a price and a stated weight. “Mined vs lab” divides the mined median by the lab-grown one.
Sapphire: lab-grown vs mined, per carat
| Loose stones | Listings | Median per carat | Middle half (25th to 75th percentile) | Typical size (median) | Largest in stock |
|---|---|---|---|---|---|
| Lab-grown | 43 | $7.92 | $5.39 to $18.86 | 2.41 ct | Gryrigns lab sapphire, 28.96 ct, emerald cut, about $75 |
| Mined, sold as natural | 87 | $2,250 | $910 to $3,000 | 2.02 ct | StarRuby.in natural star sapphire, 19.17 ct, about $7,200 |
| Lab-grown, 1 to 3 ct only | 21 | $11 | $7.28 to $14.99 | 2.14 ct | |
| Mined, 1 to 3 ct only | 56 | $2,750 | $910 to $3,190 | 1.52 ct |
At the median, mined sapphire cost about 280 times as much per carat as lab-grown sapphire. Comparing only stones of 1 to 3 carats, mined sapphire cost about 260 times as much. All of the mined listings name a lab report, and 94% are sold as unheated. Of the 87 mined sapphire listings, 64 come from one brand, StarRuby.in, so the figure largely reflects that brand’s prices.
Ruby: lab-grown vs mined, per carat
| Loose stones | Listings | Median per carat | Middle half (25th to 75th percentile) | Typical size (median) | Largest in stock |
|---|---|---|---|---|---|
| Lab-grown | 35 | $7.80 | $4.60 to $19.05 | 2.5 ct | Gryrigns lab ruby, 48.3 ct, oval, about $55 |
| Mined, sold as natural | 48 | $940 | $270 to $2,250 | 3.05 ct | StarRuby.in natural star ruby, 17.83 ct, oval, about $3,550 |
| Lab-grown, 1 to 3 ct only | 15 | $16 | $12 to $21 | 1.6 ct | |
| Mined, 1 to 3 ct only | 19 | $1,880 | $1,130 to $3,260 | 2.01 ct |
At the median, mined ruby cost about 120 times as much per carat as lab-grown ruby. Comparing only stones of 1 to 3 carats, mined ruby cost about 120 times as much. All of the mined listings name a lab report, and 96% are sold as unheated. Of the 48 mined ruby listings, 46 come from one brand, StarRuby.in, so the figure largely reflects that brand’s prices.
Emerald: lab-grown vs mined, per carat
| Loose stones | Listings | Median per carat | Middle half (25th to 75th percentile) | Typical size (median) | Largest in stock |
|---|---|---|---|---|---|
| Lab-grown | 55 | $59 | $51 to $74 | 0.86 ct | Instagem lab emerald, 11.18 to 14.79 ct, emerald cut, about $1,050 |
| Mined, sold as natural | 1 | Too few for a median | StarRuby.in natural emerald, 4.73 ct, about $16,000 |
Only 1 listing of mined emerald had a price and a stated weight at the time of the check, too few for a fair median, so the two are not compared.
Alexandrite: lab-grown vs mined, per carat
| Loose stones | Listings | Median per carat | Middle half (25th to 75th percentile) | Typical size (median) | Largest in stock |
|---|---|---|---|---|---|
| Lab-grown | 21 | $56 | $41 to $93 | 1.38 ct | Mysticdrop lab alexandrite, 18.89 to 20.08 ct, about $1,850 |
| Mined, sold as natural | 2 | Too few for a median | natural alexandrite, 0.83 ct, oval, about $8,300 |
Only 2 listings of mined alexandrite had a price and a stated weight at the time of the check, too few for a fair median, so the two are not compared. Of the 21 lab-grown alexandrite listings, 20 come from one brand, Instagem, so the figure largely reflects that brand’s prices.
Mined gems with no lab-grown version in our catalogue
| Gem | Listings | Median per carat | Middle half (25th to 75th percentile) | Typical size (median) | Largest in stock |
|---|---|---|---|---|---|
| Tanzanite | 36 | $615 | $615 to $615 | 9.86 ct | PUHARGEMS natural tanzanite, 15.65 ct, oval, about $9,600 |
| Spinel | 5 | $275 | $87 to $500 | 1.05 ct | natural spinel, 2.19 ct, emerald cut, about $190 |
| Paraiba tourmaline | 1 | Too few for a median | natural Paraiba tourmaline, 10.08 ct, oval, about $20,250 |
All 36 mined tanzanite listings come from one brand, PUHARGEMS, so the figure largely reflects that brand’s prices.
Why lab-grown stones cost so much less
A lab-grown gem is the same material as the mined one. GIA describes a synthetic gem as made in a laboratory, one that “shares virtually all chemical, optical, and physical characteristics of its natural mineral counterpart.” So the price gap is about how a stone comes to exist, not what it is made of.
Ruby and sapphire are , and corundum can be grown by flame fusion, which Auguste Verneuil announced in 1902. GIA calls it the least expensive and most common way to make synthetic corundum and spinel. Emerald and alexandrite can be grown by the flux method, and emerald also by hydrothermal growth. GIA says flux growth takes patience and significant investment, since a crystal can take up to a year to grow and the equipment is very expensive, and that hydrothermal growth is slow and expensive too. That fits the numbers above: on October 17, 2026 the lab-grown medians were $7.92 a carat for sapphire, $7.80 a carat for ruby, $59 a carat for emerald and $56 a carat for alexandrite.
A mined stone, by contrast, has to be found. The mined listings counted here are also at the fine end of the market: 98% name a report from a gem lab such as GIA, GRS or IGI, and 73% are sold as unheated. Read the mined figures as the price of fine stones sold with paperwork, not of every mined gem.
How each method works, with photos, is on how lab gems are grown, and which gems can be grown at all is on which gems can be lab-grown.
How the numbers are made
- Which listings. Every loose stone in our two catalogues: the lab-grown stones on the lab gem catalog (from a short list of lab-gem brands, with a title that says lab-grown, created or synthetic) and the mined stones on the natural gem catalog (sold as natural, most with a lab report). 556 of the 918 listings in the two catalogues are loose stones; the rest are rings, earrings, pendants, bracelets and a few rough crystals. This is a survey of the listings we follow, not of all of Amazon.
- Prices. Each price is the listing’s price from Amazon’s Creators API at the daily check (October 17, 2026, 17:26 UTC). A listing with no price at that moment is left out, so every stone counted was in stock. The page is rebuilt from that day’s prices; no price is kept from one day to the next, and when the latest check is more than 24 hours old the page shows no numbers. These are the prices sellers ask on Amazon, not what stones sell for elsewhere.
- Weight. Only the carat weight the listing states. A carat is 200 milligrams, one fifth of a gram (FTC Jewelry Guides, 16 CFR 23.18). A weight range such as “2.88 to 3.52 ct” counts as its middle, as long as the top is no more than 1.5 times the bottom. A pair is priced over the weight of both stones, and a pair never counts as the largest stone. A weight our catalogue gives as “about” was worked out from the millimetre size, not stated by the seller, so it is left out, and so is a stated weight more than 3 times off what a stone of the stated millimetre size can weigh (most likely a typo in the listing).
- Price per carat is the listing price divided by the stated weight. The median is the middle listing. The middle half runs from the 25th to the 75th percentile, so a quarter of listings are cheaper and a quarter cost more. A median needs at least 5 listings.
- Mixed groups. Each gem mixes colours, cuts and sizes, and star stones count with their gem. The 1 to 3 ct rows compare stones of similar size. A few brands list many stones each, so a figure can lean on one brand’s prices; the notes under each table say when one brand is behind at least two thirds of the listings.
- Diamonds are left out. Our lab catalogue has no loose lab-grown diamonds, and the loose natural diamonds mix colourless and fancy-coloured stones, which are priced on different scales. For lab diamond prices see how much a 1 carat lab-grown diamond costs.
- Left out (222 of 556 loose listings):
- No carat weight stated: 37
- Only a weight worked out from the millimetre size, not stated by the seller: 153
- A weight range wider than 1.5 to 1 (a choice of sizes, not one stone): 13
- A stated weight more than 3 times off what a stone of the stated millimetre size can weigh (a likely typo): 4
- Lots and parcels of several stones: 3
- A title that names a different stone: 1
- Pairs without a total weight: 2
- Diamonds, left out on purpose (see above): 9
Keep going
Frequently Asked Questions
How much does lab sapphire cost per carat?
On October 17, 2026, loose lab-grown sapphires in our Amazon catalogue had a median price of about $7.92 a carat, and the middle half of listings ran from $5.39 to $18.86 a carat (43 listings, all colours). Lab sapphire is often grown by flame fusion, which GIA calls the least expensive and most common way to make synthetic corundum.
What is the price of lab ruby per carat?
On October 17, 2026, the median loose lab-grown ruby in our Amazon catalogue cost about $7.80 a carat, with the middle half of listings running from $4.60 to $19.05 a carat (35 listings, 4 of them star rubies). Mined ruby sold as natural had a median of about $940 a carat (48 listings). Of the 48 mined ruby listings, 46 come from one brand, StarRuby.in, so the figure largely reflects that brand’s prices.
How much more does natural sapphire cost than lab sapphire?
On October 17, 2026, mined sapphire cost about 280 times as much per carat as lab-grown sapphire at the median: about $2,250 against $7.92. Comparing only stones of 1 to 3 carats, mined sapphire cost about $2,750 a carat and lab sapphire about $11 (56 and 21 listings). Among the mined listings, all name a lab report and 94% are sold as unheated, so read the figure as the price of fine mined sapphire, not of every mined sapphire. Of the 87 mined sapphire listings, 64 come from one brand, StarRuby.in, so the figure largely reflects that brand’s prices.
Why are lab gems so cheap?
A lab gem is the same material as the mined one: GIA says it shares virtually all the chemical, optical and physical characteristics of its natural counterpart. What differs is supply. Ruby and sapphire can be grown by flame fusion, which GIA calls the least expensive and most common way to make synthetic corundum, while a mined stone has to be found. On October 17, 2026, at the median of our Amazon listings, mined sapphire cost about 280 times as much per carat as lab-grown sapphire, and mined ruby about 120 times as much.
Sources
- Amazon listing prices from the Amazon Creators API, read October 17, 2026, 17:26 UTC, for the loose stones on our lab gem catalog and natural gem catalog.
- GIA, “An Introduction to Synthetic Gem Materials”: gia.edu
- FTC Jewelry Guides, 16 CFR 23.18, on carat weight (a carat is 200 milligrams): law.cornell.edu