Question 1

Is an unheated ruby worth more than a heated one?

Accepted Answer

Generally yes. At similar colour, clarity and size, an unheated ruby usually sells at a significant premium because few stones reach good quality without treatment. The size of the premium depends on the stone and on market demand. A heated ruby of excellent colour can still be worth more than an unheated stone of weak colour, so quality always comes first.

Question 2

What does "no indications of heating" mean on a report?

Accepted Answer

It is the standard way laboratories report that, after examination, they found no evidence of heat treatment. It is an opinion based on current methods, not an absolute guarantee. For higher-value stones, check which laboratory issued the report and how recent it is, since detection methods continue to improve and older reports may not reflect current knowledge.

Question 3

Can heating be detected in every ruby?

Accepted Answer

No. Heating at high temperatures usually leaves clear evidence, but gentle low-temperature heating can be very difficult to identify, particularly in stones with few inclusions. This is one reason laboratories sometimes reach different conclusions on the same stone, and why buyers of important rubies may seek reports from more than one recognised laboratory.

Question 4

Do unheated rubies only come from Burma?

Accepted Answer

No. Unheated rubies come from several sources, including Myanmar, Mozambique, Sri Lanka and Tanzania. Burmese stones are the best known, and Mozambique has produced a significant number of fine unheated rubies since its deposits were discovered in 2009. A laboratory report will usually give an origin opinion alongside the treatment findings.

Unheated Rubies