How Semi Precious Gemstones Are Graded: A Complete Guide to Clarity & Color

You'd have seen terms like AAA, AA, A or B grade or even something called 'inclusions' whenever you have browsed through a gemstone website and it must have been confusing, especially if you are a beginner, I get it.

Sellers often charge high on the basis of a stone's color and clarity grade but how would you ensure if you are getting your money's actual worth? How can you trust whether that AAA grade tag on that pretty sapphire is even a real one? In this article, we'll uncover the same helping you understand gemstone grading in a  simple, visual, and practical way. Whether you're a buyer, collector, jeweler, or enthusiast, use this guide to compare gemstone quality confidently and understand the factors that drive pricing, especially when you’re planning to buy gemstones online.

What Is Gemstone Grading?

Firstly let's understand what is grading exactly and why it is so dear to both sellers and buyers. Gemstone grading is a systematic method used to evaluate the overall quality of a stone based on various factors such as color, clarity, cut, and carat weight. Now for semi-precious stones like amethyst gemstone, moss agate, and labradorite crystal, the focus is primarily on color vibrancy and internal clarity, as these affect how appealing and valuable the gem appears, however for precious gemstones like diamonds, sapphires, rubies... all four Cs play an equal role.

The Gemstone Grading System Explained

There is no strict international standard for grading semi-precious stones, but most sellers and gemologists use a version of the AAA–A–B grading system.

AAA Grade Gemstones

• Top 10% of stones available
• Rich, saturated color
• Nearly flawless clarity
• Excellent polish and symmetry
• AAA grade gemstones meaning = highest quality in commercial markets
• AA Grade
• Good color (slightly lighter or less saturated)
• Minor inclusions
• Still suitable for high-end jewelry

A Grade

• Commercial quality
• Noticeable inclusions
• Often used in costume jewelry or wire wrapping

B Grade & Below

• Uneven color
• Visible inclusions, cracks, or cloudiness
• Often used for decorative purposes or metaphysical healing

📌 Tip: When shopping for amethyst crystals for sale, knowing this scale helps you distinguish between a vibrant collector’s piece and a dull, mass-market stone.

📌 Point to be noted: While in most cases inclusions often lead a stone down the scale in the grading system, for many stones, inclusions are the one that make a stone heavily valued. A few examples of the same are :

• Silk and Feather Inclusion in Sapphire
• Jardin inclusion in Emerald
• Tiger stripe inclusion in amethyst
• Enhydro inclusions in Quartz

Read our article on the different types of amethyst available in the market and how to choose one for yourself. 

Looking to compare gemstone prices beyond opals? Learn how to calculate cost per carat for bulk gemstone purchases to make smarter buying decisions.

Gemstone Clarity: What to Look For

The gemstone clarity scale explained is similar to the one used for diamonds but adjusted for each stone type. For instance, it’s normal for moss agate to have inclusions (they’re what give it the mossy appearance), while amethyst is more prized when free of visible flaws.

💎 Common Clarity Grades:

When comparing gemstone quality, especially online, clarity matters—but not equally for every stone. That’s where a gemstone clarity comparison chart becomes essential.

Gemstone Color Grading: Saturation, Hue & Tone

Gemstone color grading evaluates three primary aspects:

• Hue – The actual color (purple, green, blue, etc.)

• Tone – How light or dark the color is

• Saturation – Intensity or vividness of the color

Example:

A premium amethyst has a deep, royal purple hue with even saturation.

Lower grades may appear washed-out, too pale, or overly dark (almost black).

📌 For buyers exploring labradorite crystals online, look for vibrant flashes of blue, green, or gold—dull labradorite is considered lower grade.

Did you know - Labradorite and spectrolite, two stones that are often confused for one another, happen to have very different energetic properties. Learn more about which one’s got stronger properties and how to choose the correct one for yourself. 

Before you buy, make sure you read our Ultimate Opal Buying Guide—a complete resource for choosing the right opal at the right price.

Grading in Practice: How Jewelers Use It

Professional jewelers use gemstone grading to:

• Set accurate pricing

• Choose stones for custom designs

• Determine investment or resale value

They rely on reference materials like a gemstone quality chart and often use tools like:

• 10x magnification loupes

• Calibrated color comparison stones

• Spectrometers for advanced analysis
  

💡 Beginner Tip: If you’re just starting out, use a gemstone quality guide for beginners (many sellers provide this in product listings or via blog posts).

Opals under $500 are great, but don’t miss our guide to 20 affordable gemstones perfect for jewelry makers.

How to Identify Gemstone Quality (Even as a Beginner)

Here’s a checklist anyone can use when evaluating a semi-precious stone:

✅ Is the color rich and evenly distributed?

✅ Are there visible cracks, inclusions, or cloudiness?

✅ Is the cut clean and symmetrical?

✅ Does the surface have a polished, professional finish?

✅ Has the seller provided a gemstone grading chart or certification?

You can use this method across categories—from finding loose Moss Agate stones for sale to browsing high-quality Certified Opal crystals online.

Ever wondered why opal prices vary so much? We did too, and here’s the answer to your questions. 

Conclusion: Knowledge Is Power (and Protection)

Understanding the gemstone grading system empowers you to make smarter, more confident buying decisions—whether you’re shopping for yourself or clients. It also protects you from overpaying for subpar stones marketed with inflated terms.

Next time you’re browsing listings on trusted sites like GemstonesForSale or exploring AAA grade gemstones, revisit this guide to ensure you’re investing in real value—not just shine.