Gemstone guide

About Gemstones

Gemstone species, colors, cuts, and qualities—and the details that help you understand and compare stones.

Shop loose gemstones Browse the guides

The short version

What a gemstone is, and why it costs what it costs

Gemstones have captivated people for thousands of years — admired for their beauty, valued for their rarity, and cherished for their symbolism. Whether you're a collector, a jeweler, or someone looking to make an informed purchase, understanding gemstones is the key to choosing pieces that truly speak to you.

At Sapphire Row, every listing states whether a stone is natural, lab-grown or cultured. This page is your foundation; the guides further down go deep on one stone at a time.

Formation

How gemstones are formed

Most gemstones are created deep within the earth under extreme heat and pressure. Over millions of years, geological movement brings them closer to the surface, where they can be mined. Each type of gemstone has a unique formation process, which influences everything from color to inclusions.

Some stones, such as diamonds, form under intense pressure; others, like opals, form from mineral-rich water in sedimentary environments. This diversity in formation is what gives each gemstone its character and uniqueness.

Collection tray of loose gemstones with carat labels

Valuation

What makes a gemstone valuable?

Value is determined by several universal factors. They are not weighted equally, and the weighting shifts from species to species.

The most important factor for most gemstones. Rich, pure, evenly distributed color typically commands higher value — and the hue that counts as fine differs from one species to the next.

Refers to the presence, or absence, of natural inclusions. Some inclusions are acceptable, even expected, depending on the stone.

A well-cut gemstone maximizes brilliance, enhances color, and improves symmetry. Cuts vary by shape and purpose.

Larger gemstones are rarer and often significantly more valuable. The relationship between size and value is not linear — it increases sharply with rarity.

Certain origins, such as Burmese rubies or Ceylon sapphires, are culturally renowned and often command premium prices.

Many gemstones undergo traditional treatments, such as heating, to improve color and clarity. Untreated stones are significantly rarer and more valuable.

Choosing

How to choose the right gemstone

Four questions, in this order. Answer them and the field narrows quickly.

01

Purpose

Everyday wear, special occasions, or a collection.

02

Durability

Some stones require more care than others.

03

Symbolism

Birthstones, emotional meaning, or historical significance.

04

Budget

Price varies widely by type, quality, and rarity.

The guides

Explore individual gemstones

History, characteristics, treatments, rarity and buying tips — one guide per stone, with what we are currently holding.

Rubies496 in stock Read guide Sapphires2,262 in stock Read guide Emeralds470 in stock Read guide Alexandrites187 in stock Read guide Tanzanites166 in stock Read guide Opals227 in stock Read guide Aquamarines289 in stock Read guide Tourmalines256 in stock Read guide Garnets377 in stock Read guide Amethysts336 in stock Read guide Peridots148 in stock Read guide Citrines269 in stock Read guide Spinels130 in stock Read guide Zircons86 in stock Read guide Morganites51 in stock Read guide
Shop all gemstones

How grading works

Reading a grade

Grading is two different systems wearing similar words. These guides keep them apart.

For diamonds

For colored stones

For both

Pricing & sourcing

Understanding pricing and transparent sourcing

Professional sourcing and transparent pricing. What we commit to on every stone is below.

GIA sapphire origin report with details for blue oval sapphires in white metal necklace.

Accurate disclosure of treatments

Treatment is stated wherever it is known. Where a treatment is standard for the species, we say so rather than leaving you to guess.

Clear disclosure of lab reports

Many of our stones come with a lab report. When a stone has one, the lab and report number are on its page.

Transparency in pricing and origin

Transparent pricing, with treatment and origin stated wherever they are known.

New Gemstones

Shop new arrivals

0.23 ct Natural Diamond – F VVS1 – Round Cut – GIA Certified — Sapphire Row · cut7
0.23 ct Natural Diamond – F VVS1 – Round Cut – GIA Certified
$535
$535
0.23 ct Natural Diamond – F VVS1 – Round Cut – GIA Certified — Sapphire Row · cut7
0.23 ct Natural Diamond – F VVS1 – Round Cut – GIA Certified
$535
$535
0.23 ct Natural Diamond – E IF – Round Cut – GIA Certified — Sapphire Row · cut7
0.23 ct Natural Diamond – E IF – Round Cut – GIA Certified
$535
$535
0.23 ct Natural Diamond – F VVS1 – Round Cut – GIA Certified — Sapphire Row · cut7
0.23 ct Natural Diamond – F VVS1 – Round Cut – GIA Certified
$535
$535
0.23 ct Natural Diamond – E VVS1 – Round Cut – GIA Certified — Sapphire Row · cut7
0.23 ct Natural Diamond – E VVS1 – Round Cut – GIA Certified
$535
$535
0.23 ct Natural Diamond – F VVS1 – Round Cut – GIA Certified — Sapphire Row · cut7
0.23 ct Natural Diamond – F VVS1 – Round Cut – GIA Certified
$535
$535
0.23 ct Natural Diamond – E VVS1 – Round Cut – GIA Certified — Sapphire Row · cut7
0.23 ct Natural Diamond – E VVS1 – Round Cut – GIA Certified
$535
$535
0.23 ct Natural Diamond – E VVS1 – Round Cut – GIA Certified — Sapphire Row · cut7
0.23 ct Natural Diamond – E VVS1 – Round Cut – GIA Certified
$535
$535
0.23 ct Natural Diamond – E VVS1 – Round Cut – GIA Certified — Sapphire Row · cut7
0.23 ct Natural Diamond – E VVS1 – Round Cut – GIA Certified
$535
$535
0.23 ct Natural Diamond – E VVS1 – Round Cut – GIA Certified — Sapphire Row · cut7
0.23 ct Natural Diamond – E VVS1 – Round Cut – GIA Certified
$535
$535