What Is Paraíba Tourmaline? Rarity, Origin, and the Value of Unheated Stones

Paraíba tourmaline is a rare copper- and manganese-bearing tourmaline prized for its electric blue-green glow. Learn what defines it, how Brazilian and Mozambican origins differ, why most stones are heated, and how certification and unheated status determine collector value.

What Is Alexandrite? Colour Change, Origin Rarity & Untreated Certification

Alexandrite is a rare chromium-bearing chrysoberyl that turns green in daylight and red under incandescent light. A complete guide to what drives its colour change, how Russian and Brazilian origins compare at auction, and why untreated stones with international lab reports define collector-grade quality.

What Are Natural Colored Gemstones? Untreated vs. Heated, Certification & Origin Rarity

A collector's guide to natural colored gemstones: what "natural" really means, why it isn't the same as unheated, how to read no-heat and clarity-enhancement conclusions on GRS, Gübelin and SSEF reports, and what record-setting Burmese ruby, Kashmir sapphire and Colombian emerald sales reveal about rarity — from JUSTLEE, curators of unheated gemstones for over fifty years.

The Ruby Collector's Guide: Pigeon Blood, Origin, Unheated Status, and International Certification

The ruby is the red, chromium-coloured member of the corundum family, and its collecting value turns on four dimensions: colour grade, origin, treatment status, and certification. The finest are graded Pigeon Blood and prized above all for being unheated, with no indications of heating. This guide explains ruby colour grading, distinguishing Burmese from Mozambican origin, why unheated status is central to collecting, and how GRS, GIA, SSEF, Gübelin, and AIGS certification is read.

What Is a Kashmir Sapphire? Velvety Glow, Unheated Rarity, and How to Read the Certification

Kashmir sapphires come from a Himalayan deposit exhausted over a century ago, so every collectible stone traces to a brief extraction window in the 1880s. Their signature velvety glow arises from fine silk inclusions that cannot be reproduced; the finest are graded Royal Blue and remain unheated, with no indications of heating. This guide explains the colour, the rarity, the unheated condition, and how GRS, GIA, SSEF, Gübelin, and AIGS certification is read.

What Is an Unheated Gemstone? From Lab Reports to the Collector's Standard

"Unheated" is a laboratory conclusion, not a seller's claim. Learn how GRS, Gübelin, SSEF, and GIA record treatment status, why emeralds follow a different standard, and what mine closures mean for long-term supply. JUSTLEE fifty years' curatorial standard explained.