Moijey Fine Jewelry & Diamonds Blog

Ruby - The King of Gems

Originally posted on June 29th, 2017

Updated April 13th, 2020

The title is no joke. Rubies in the Sanskrit language are called Ratanaraj, the king of precious stones.


Ruby is one of the rarest gemstones in the world. Ruby costs more per carat than any other gemstone. It is a variety of the gem species corundum, which is also related to Sapphire, another impressive variety of corundum. There are traces of chromium in ruby's aluminum oxide structure, causing the iconic fiery red.

What makes Ruby unique is that the chromium in its crystal structure causes fluorescence. Fluorescence is the light that some gemstones emit when exposed to ultraviolet (UV) rays. Romantically, ruby's red becomes firey and more intense when it's out in sunlight.


Ruby is an ideal alternative to diamond engagement because they're nine on the Mohs scale of hardness. An excellent choice, considering rubies are associated with the blood of life, the fire of life, and passion. Rubies are said to bring harmony to their owners and to provide a peaceful existence with neighbors. Those are excellent qualities for an engagement ring!


It's an exciting time for us here at Moijey because we will be focusing on rubies (July's birthstone) for a whole month. We'll dive into how rubies form and how precious - figuratively and literally - they are to a wide variety of people.