In most markets, pure red colors command the highest prices and ruby with overtones of orange and purple are less valued. The color must be neither too dark nor too light to be considered …

Increasing demand for ruby alternatives rekindled appreciation for spinel’s rich red color and history. In ancient times, southeast Asia’s mines yielded exceptional large spinel crystals, …

The term “star sapphire” encompasses all colors of star corundum except red, which is called star ruby. Naturally, some colors of star corundum are valued more highly than others.

The fact that a ruby comes from a famous mine doesn’t mean it is good quality. But fine-quality rubies that have documentation of Myanmar (Burmese) origin from an independent laboratory …

In general, red spinel is the most desirable, followed by fine cobalt-blue spinel, then by vibrant hot pink and vivid orange stones. Violet and bluish purple to purple, or lavender, stones tend to be …

Aug 7, 2017 · Following the charts for the micro-features of emerald and sapphire—published in Winter 2016 and Summer 2017, respectively—this chart on ruby rounds out G&G ’s series on …

2 days ago · Rubies found in marble deposits often have a vibrant red glow. Marble has low iron content, so the rubies that originate in marble (called “marble-hosted” by gemologists) lack …

Numerous natural-looking dark red solid inclusions are observed in a flame-fusion laboratory-grown ruby.

May 22, 2025 · Fluorescence happens when certain elements and crystal defects inside a gem get “excited” by ultraviolet rays and respond by glowing in vibrant colors, such as blue, green, …

This series represents a specific form of hydrogen incorporation in the corundum structure that is a diagnostic indicator of heat treatment for certain types of ruby and sapphire, particularly ruby …