Gemstone Grading Guide

Gemstone Quality

Gemstone Grading Guide

Natural gemstones are formed by the earth — no two are identical. Understanding how they are assessed helps you choose with confidence and appreciate what makes each piece unique. This guide explains how MXW grades every gemstone in our range, and why a grade means something different from one stone to the next.

A note on grading: There is no single universal standard for gemstone grading. The letter grades used across the industry — A, AA and AAA — are defined by each seller based on their own sourcing range and quality criteria. The grades on this page reflect MXW's own quality standards, applied consistently across our range and aligned with the standards of the specialist suppliers we source from.

Grades Are Relative to Each Stone

This is the most important thing to understand about gemstone grades. A grade is judged against the best that particular stone naturally occurs in — not against other gemstones. AAA pink opal is assessed against how fine pink opal can be; AAA labradorite against how fine labradorite can be. They share the same top grade, but they are graded on different scales.

This means a AAA grade does not make two different stones equal in rarity, value or price. Each stone forms differently in nature, so a AAA of one gemstone and a AAA of another are each the top of their own kind. A grade tells you how good a stone is for its type — the finest quality that stone naturally comes in.

Because every gemstone is different, the qualities that define a high grade shift from stone to stone. What makes a pink opal exceptional is not what makes a labradorite exceptional. The four factors below are assessed for every stone, but their relative importance depends on the gemstone.

01
Colour
Richness and evenness of colour across the stone
02
Clarity
How clean and free of visible marks the stone is
03
Cut & Polish
Quality of shaping, finish and surface lustre
04
Consistency
Uniform shape and matching across a strand of beads

The A–AAA Scale

Our Grading Range

MXW grades gemstones on the A–AAA scale commonly used in the gemstone bead trade and by our specialist suppliers. Each grade reflects the combined quality of colour, clarity, cut, polish and finish — always judged against the best that particular stone naturally occurs in.

Grade Quality What You See
AAA
Finest The best quality that stone naturally comes in. Rich, even colour, excellent polish and lustre, and consistent shape across the strand. Cleanly finished beads with well-positioned drill holes. This is our top tier.
AA
High Strong, even colour and a smooth, well-polished finish. Minor natural variation may be visible on close inspection. A high-quality choice for semi-fine jewellery.
A
Good Good colour and a sound cut, with natural inclusions, surface features or colour variation visible on inspection. The stone may appear less bright or consistent than higher grades.
Beyond AAA: Some suppliers use labels such as AAAA or “museum grade”. These terms have no agreed industry definition and are often used primarily for marketing, so MXW does not use them. We use a clear A–AAA scale and grade conservatively — we would rather a piece exceed your expectations than fall short of an inflated label.

Natural & Undyed

How We Source

We source natural gemstones that are undyed — the colour you see is the stone's own, never added. This is why natural variation between pieces is expected and celebrated. A dyed stone may appear highly uniform, but it is no longer showing its original natural colour.

Undyed means unique. Slight differences in shade, translucency and natural markings from one piece to the next are signatures of genuine gemstone material. Each gemstone is unique, and product photographs are representative examples of the colour and grade you can expect.

Have a question about gemstone quality or want to understand the grade used for a specific product? Reach out at info@mxwjewellery.com — we are happy to help you choose.

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