The Majestic Library

Diamond & Gemstone Guides

Understand diamonds and coloured gemstones — the 4Cs, independent grading, lab-grown versus natural, diamond shapes and gemstone types, all set in solid gold.

Where to start

A diamond's beauty comes down to the 4Cs — cut, colour, clarity and carat — with cut mattering most. Every diamond we supply is independently graded: lab-grown by IGI, natural by GIA or HRD. Coloured gemstones like ruby, sapphire and emerald are chosen on colour first. The guides below explain each, and every stone is set in solid 9, 14 or 18ct gold, made to order or bespoke. Ready to browse pieces? See Gemstones & Diamonds to shop.

Diamonds explained

Lab-Grown Diamonds

How they're grown, graded and priced.

Natural Diamonds

How they form, and the 4Cs that set value.

Lab-Grown vs Natural

The difference, and how each is graded.

IGI-Certified Diamonds

What a grading report is and how we grade.

Diamond 4Cs Guide

Cut, clarity, colour and carat — how they balance.

The 4Cs in depth

Diamond Cut Quality

The most important C — proportions and sparkle.

Diamond Colour Grades

The D-Z scale and the near-colourless sweet spot.

Diamond Clarity

Inclusions, the FL-I3 scale and eye-clean value.

Diamond Carat Weight

Weight vs face-up size, and magic weights.

By diamond shape

Oval

Brilliant sparkle, elongating, large for its weight.

Cushion

Soft corners, vintage warmth, modern brilliance.

Emerald Cut

Step facets and an elegant hall of mirrors.

Asscher

A square step cut with Art Deco depth.

Marquise

Elongated, dramatic, large for its carat.

Pear

A brilliant teardrop that flatters the hand.

Coloured gemstones

Emerald

Colour, care and setting the May birthstone.

Ruby

The July birthstone — vivid red, superbly hard.

Sapphire

Blue and beyond — the September birthstone.

Morganite

Romantic peachy-pink, lovely in rose gold.

Amethyst

February's purple quartz, choosing and wearing.

Peridot

August's fresh lime-to-olive green.

Turquoise

December's sky-blue stone — colour, care and crosses.

Related reading

See also: Shop diamond & gemstone jewellery · Engagement ring guides · Diamond shapes guide · 9ct vs 14ct vs 18ct gold · Back to The Majestic Library

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