From the deep blue of a sapphire to the warm glow of a citrine, gemstones have captivated us for centuries — not just for their beauty, but for the stories they carry and the moments they mark. Whether you are selecting a gift, building a personal collection, or simply trying to understand what makes one stone different from another, a working knowledge of gemstones from A to Z is one of the most rewarding things a jewelry lover can have. This guide is designed to give you exactly that: clear, honest information about the stones you are most likely to encounter.

Understanding What Makes a Gemstone

A gemstone is any mineral, organic material, or crystal that has been cut and polished for use in jewelry. Most are valued for a combination of three qualities: color, clarity, and durability (measured on the Mohs hardness scale). A few — pearl, amber, and coral among them — are organic rather than mineral in origin, which makes them unique in the gem world.

Gemstones are broadly divided into two categories:

• Precious stones: Traditionally, diamond, ruby, emerald, and sapphire hold this designation. They are generally rarer, harder, and command higher prices.
• Semi-precious stones: Everything else — amethyst, garnet, topaz, peridot, turquoise, and dozens more. “Semi-precious” does not mean inferior; some semi-precious stones are rarer or more valuable than their precious counterparts.

A Closer Look: Gemstones A to Z

The gemstone alphabet is surprisingly rich. Here is a representative tour through stones you are most likely to see in fine jewelry settings:

• Alexandrite: One of the rarest and most fascinating stones, alexandrite shifts from green in daylight to red under incandescent light. A true color-change phenomenon.
• Amethyst: A member of the quartz family with a distinctive violet-to-purple color range. February’s birthstone, and historically associated with clarity of mind.
• Aquamarine: A cool, sea-blue variety of beryl. The name comes from the Latin for “water of the sea,” and it wears particularly well in pieces suited to the coast — something our customers at the Jersey Shore tend to appreciate.
• Citrine: A warm golden-yellow quartz, often mistaken for topaz. Citrine is November’s birthstone and one of the more affordable yellow stones available.
• Diamond: The hardest natural substance on earth (10 on the Mohs scale) and the most sought-after gemstone. Available today as both natural and lab-grown, each certified for quality.
• Emerald: The rich green variety of beryl, colored by trace amounts of chromium. Inclusions within an emerald are so common they have their own French term: jardin (garden).
• Garnet: Often thought of as red, garnet actually comes in nearly every color. Tsavorite garnet is a vivid green that rivals emerald; demantoid garnet has exceptional brilliance.
• Moonstone: Prized for its adularescence — a soft, billowing light that seems to float beneath the surface. A favorite in vintage-inspired and artisan designs.
• Opal: Each opal is unique, displaying shifting plays of color called “fire.” Opals require gentle care, as they contain water and can be sensitive to dryness or sharp impact.
• Peridot: One of the few gemstones that forms in only one color — olive green — caused by iron content. August’s birthstone.
• Ruby: The red variety of corundum, colored by chromium. Fine rubies of Burmese origin are among the most valuable gemstones per carat in the world.
• Sapphire: Also corundum, available in virtually every color except red (which becomes ruby). The classic blue sapphire remains enduringly popular in engagement rings.
• Tanzanite: Found only near Mount Kilimanjaro in Tanzania, tanzanite has a remarkable blue-violet color and has been commercially available for less than sixty years — making it genuinely rare.
• Topaz: Naturally colorless, topaz is most often treated to produce the familiar blue variety. Imperial topaz, in shades of orange and pink, is the stone’s most prized natural form.
• Tourmaline: Perhaps the widest color range of any gemstone. Bi-color and watermelon tourmalines — showing two or more hues in a single stone — are especially striking.
• Turquoise: One of the oldest gemstones in continuous use, with a history spanning cultures and continents. Its sky-blue color is unmistakable and lends itself beautifully to warm-weather jewelry.
• Zircon: A natural gemstone (distinct from cubic zirconia, which is synthetic) with impressive brilliance and fire. Blue zircon in particular is a beautiful and underappreciated choice.

Birthstones and Their Significance

Many customers come to us looking for a birthstone gift, and it is one of the most personal ways to choose a piece of jewelry. The modern birthstone list, standardized in the early twentieth century, assigns at least one stone to each month. Several months have more than one option — June, for instance, claims pearl, alexandrite, and moonstone — giving you meaningful flexibility when selecting a piece.

Birthstone jewelry is a thoughtful choice for milestones: a child’s birth, a significant birthday, a graduation, or simply a way to honor someone whose month holds meaning for you.

Caring for Your Gemstones

Not all gemstones are created equal when it comes to durability, and understanding the basics of care will protect your investment for years to come.

• Hard stones (diamond, sapphire, ruby, topaz) are generally safe for ultrasonic cleaning and everyday wear, though even diamonds can chip if struck at the right angle.
• Softer or more delicate stones (opal, pearl, emerald, turquoise) should be cleaned gently with a soft, damp cloth and kept away from harsh chemicals, heat, and ultrasonic cleaners.
• Treated stones — including many blue topazes, fracture-filled emeralds, and heat-treated sapphires — require special consideration. It is always worth asking whether a stone has been treated before committing to a cleaning method.

When in doubt, bring the piece in. Our team at M.S. Brown Jewelers is happy to assess your jewelry and recommend the right approach.

Frequently Asked Questions

What is the difference between a natural gemstone and a lab-created one?

A natural gemstone forms in the earth over thousands to millions of years. A lab-created stone is grown in a controlled environment using the same chemical composition and crystal structure as its natural counterpart — it is not an imitation or simulant. Both are real gemstones. The primary differences are origin, rarity, and price. At M.S. Brown Jewelers, we carry both natural and lab-grown options, particularly in diamonds, and we are glad to walk you through the distinctions so you can make the choice that is right for you.

Are semi-precious gemstones less valuable than precious ones?

Not necessarily. The terms “precious” and “semi-precious” are traditional rather than scientific, and they do not reliably indicate value. A fine alexandrite, for example, can be far more valuable per carat than a low-quality ruby. Rarity, color quality, size, and origin all play significant roles in determining what a gemstone is worth.

How do I know if a gemstone in a piece of estate jewelry is genuine?

The most reliable way is to have the piece examined by a trained gemologist. Visual inspection under magnification, combined with basic testing instruments, can identify most stones accurately. If you have inherited jewelry or found a piece at an estate sale, bring it in for an appraisal — it is the only way to know what you truly have.

Which gemstones are best suited to an engagement ring?

Durability is the primary consideration for a ring worn every day. Diamond (Mohs 10), sapphire, and ruby (both Mohs 9) are the most practical choices for center stones in an engagement ring. Moissanite and certain garnets are also durable enough for daily wear. Softer stones like opal, pearl, or emerald can work beautifully in engagement rings, but they require more careful wear and maintenance. We are happy to discuss the full range of options with you in person.

Whether you are drawn to the timeless depth of a sapphire, the vivid summer warmth of a peridot, or the quiet elegance of a freshwater pearl, there is a gemstone suited to every occasion and every person. We invite you to stop by either of our M.S. Brown Jewelers locations — in Wildwood on Pacific Avenue or in Cape May Court House — to see these stones in person and talk through your options with someone who genuinely enjoys the conversation. There is no substitute for holding a piece of jewelry in your hands, and we are always glad to help.