What Is a Gemstone? A Complete Guide from a Trusted Largo Jeweler

At Arnold Jewelers, we have helped generations of Tampa Bay families buy, design, and care for gemstone jewelry for more than 40 years. One of the most common questions we hear in our showroom is surprisingly simple:

“What is a gemstone, really?”

With today’s market offering natural, treated, and lab-created stones, understanding the true definition of a gemstone has never been more important—especially when you are shopping for fine jewelry in Largo, Clearwater, or anywhere in the Tampa Bay area.

This guide explains what qualifies as a gem, how natural and synthetic gemstones differ, and how to shop with confidence.

Quick Facts About Gemstones

• A gemstone is a natural or lab-created material that is cut and polished for use in jewelry.

• Most are minerals, but some are organic (such as pearl, coral, and amber).

• Natural gems and lab-created gemstones can look identical, but they differ in origin and rarity.

• Many gems are treated or enhanced to improve appearance.

• Buying from a trusted local jeweler helps ensure proper disclosure and long-term value.

What Is a Gemstone?

A gemstone is a material, most commonly a mineral, that is selected, cut, and polished specifically for use in jewelry because it offers:

• beauty

• durability

• and relative rarity

In professional gemology, the word gemstone does not simply mean “a pretty stone.” It refers to a material suitable for long-term wear and certified to meet accepted standards for jewelry use.

Gems are typically evaluated based on:

• color and visual appeal

• clarity and surface quality

• ability to take and hold a polish

• resistance to everyday wear

Only a very small portion of all minerals found in nature ever becomes gemstones.

Natural vs. Synthetic Gems – What’s the Difference?

One of the biggest sources of confusion for buyers today is the difference between natural gemstones and synthetic (lab-created) gemstones.

Natural Gemstones

A natural gemstone forms inside the earth through geological processes such as heat, pressure, and crystallization. These stones are mined from the ground and then cut and polished for jewelry.

Examples include:

• natural sapphire

• natural emerald

• natural ruby

• natural diamond

Because natural stones are formed by nature and occur in limited supply, rarity plays a major role in their long-term value.

Synthetic (Lab-Created) Gemstones

A synthetic gem, also called a lab-created or laboratory-grown gemstone, has the same chemical composition and crystal structure as its natural counterpart.

The difference is where and how it forms.

Instead of growing underground over millions of years, lab-created gems are grown in controlled laboratory environments.

Important facts about synthetic gemstones:

• They are real gemstones from a scientific standpoint.

• They are not imitations or glass.

• They are usually more affordable than natural stones.

• They are not considered rare.

Natural vs. Synthetic – Why the Difference Matters

Although natural and lab-created gemstones may look identical, they differ in:

• rarity

• collectability

• long-term resale value

• emotional and historical significance

For many buyers, especially those purchasing engagement rings, heirloom jewelry, or vintage pieces, natural gemstones remain the preferred choice.

At Arnold Jewelers, we always disclose whether a gemstone is natural or lab-created so our customers can make informed decisions.

What Qualifies a Stone as a Gemstone?

To be classified as a gemstone, a material must typically meet three professional criteria:

✔ Beauty

The stone must display attractive color, transparency or translucency, and visual appeal when cut.

✔ Durability

Gemstones must withstand everyday wear. This is evaluated by looking at:

• hardness (resistance to scratching)

• toughness (resistance to chipping or breaking)

• stability (reaction to heat, light, and chemicals)

✔ Rarity

The scarcer a gemstone is in fine quality, the higher its potential value.

This is why stones such as ruby, emerald, and fine sapphire command significantly higher prices than more abundant materials.

Are All Gemstones Minerals?

Most gemstones are minerals, but not all.

Some gemstones are organic, meaning they are formed by living organisms rather than geological processes.

Organic gemstones include:

• pearls

• coral

• amber

They are still considered gemstones when they meet jewelry-quality standards.

Treatments & Enhancements (Very Important to Know)

Many gemstones are enhanced to improve appearance.

Common industry treatments include:

• Heat treatment – common for sapphire, ruby, aquamarine

• Oiling or filling – common for emerald

• Irradiation – used for some topaz and diamonds

• Dyeing – sometimes seen in quartz or jade

Treatments are accepted in the trade when disclosed, but they affect:

• value

• durability

• cleaning methods

• long-term stability

Professional jewelers should always disclose known treatments.

Why the Mohs Hardness Scale Matters

Hardness alone does not determine wearability, but it is critical for everyday jewelry.

Gemstone	Mohs Hardness
Diamond	10
Sapphire / Ruby	9
Topaz	8
Emerald	7.5–8
Aquamarine	7.5–8
Amethyst	7
Opal	5.5–6.5

For engagement rings and daily wear, stones above 7 on the Mohs scale are typically recommended.

Vintage vs. New Jewelry – Real Differences

Vintage & Estate Gemstone Jewelry

• larger gemstones for the price

• craftsmanship from historic eras

• discontinued cuts and styles

• true one-of-a-kind pieces

New Gemstone Pieces

• modern engineering

• lighter, more comfortable settings

• easier customization

• ideal for personal designs

Both options offer excellent value when properly evaluated.

Why Buying from a Family-Owned Jeweler Matters

Large chain retailers often prioritize volume and branding over gem quality.

A family-owned jeweler provides:

• transparent information

• realistic value comparisons

• long-term care and repair services

• personal accountability

For more than four decades, Arnold Jewelers has helped Tampa Bay customers build meaningful gemstone collections with confidence.

Where to Buy Gemstone Jewelry in Tampa Bay

The safest way to buy  jewelry is through an established jeweler who:

• has a physical showroom

• employs trained professionals

• discloses treatments and origin

• offers post-purchase support

At Arnold Jewelers in Largo, we proudly serve:

• Largo

• Clearwater

• St. Petersburg

• Tampa Bay

• Online Shoppers- Free shipping!

Our jewelry selection includes:

• natural gem rings and pendants

• vintage and estate gemstone jewelry

• modern designs

• custom  settings

Shop Vintage & New Gemstone Jewelry in Tampa Bay

If you are looking for authentic  jewelry and expert guidance on natural versus lab-created stones, visit Arnold Jewelers in Largo, Florida, proudly serving customers from Clearwater, St. Petersburg, and throughout Tampa Bay.

👉 Explore our vintage gemstone jewelry.
👉 Shop our new gemstone designs.
👉 Ask about custom gemstone jewelry.