Serendib Gemstones

Knowledge Centre

Expert-written guides on Ceylon sapphires, heat treatment, certification, and buying advice — by people who source these stones at the mine in Sri Lanka. Everything you need to buy, invest, and collect with confidence.

Browse by Topic

Explore Our Guides

Natural Sapphires

Colour varieties, origins, quality factors, and what makes Ceylon sapphires the world's most sought-after.

4 guidesExplore →

Buying Guide

How to buy with confidence — certification, pricing, red flags, and what to prioritise at every budget.

1 guideExplore →

Treatments & Enhancements

Heat treatment, beryllium diffusion, lead-glass filling — what they are, how to detect them, and why they matter.

3 guidesExplore →

Certification & Grading

GIA, GRS, Gübelin — understanding laboratory reports, origin determination, and what certificates really tell you.

3 guidesExplore →

Sri Lanka & Origins

2,500 years of gemstone heritage — mining regions, geology, and why this island produces the finest sapphires on earth.

2 guidesExplore →

Featured

Most Popular Guides

Sapphires5 min read

What is an unheated sapphire?

Over 95% of commercial sapphires are heat-treated. An unheated stone is the rare exception — here is why that matters.

Read guide →
Certification4 min read

GIA vs GRS: which certificate is better?

Both laboratories are internationally respected, but they serve different buyers. Here is how to choose.

Read guide →
Sapphires5 min read

Ceylon vs Kashmir sapphire

Kashmir stones are virtually unobtainable. Ceylon sapphires are the finest accessible alternative.

Read guide →
Buying4 min read

Are unheated sapphires worth more?

Yes — by 2 to 5 times. Here is the market data and why the premium is structural.

Read guide →

All Guides

Sapphires

What is an unheated sapphire?

Sapphires

What is a Padparadscha sapphire?

Sapphires

What is a star sapphire?

Sapphires

Ceylon vs Kashmir sapphire

Certification

GIA vs GRS: which certificate is better?

Certification

What does "no heat" mean on a certificate?

Certification

How is sapphire origin determined?

Buying

Are unheated sapphires worth more?

Quick Answers

Frequently Asked Questions

Direct answers to the questions we hear most — from first-time buyers to experienced collectors.

?

How much is a blue sapphire worth?

?

What is the best colour for a blue sapphire?

?

How can you tell if a sapphire is real?

?

Are sapphires a good investment?

?

Why are Ceylon sapphires so expensive?

?

Is a GIA certificate worth it for a sapphire?

Gemstone Library

In-Depth Gemstone Guides

Comprehensive, encyclopedic guides to individual gemstone species — everything from origins and quality factors to investment value and care.

Blue Sapphire Guide
Padparadscha Guide
Ruby Guide

Have a question we haven't covered?

Our founders are always happy to share their knowledge — whether you're researching a purchase, evaluating a certificate, or just curious about gemstones.

Ask Us Anything