What Color is a Ruby

Rubies are by definition a medium to dark tone, primarily colored red. This means light colors in rubies are not rubies, but pink sapphires. Rubies do not always have a pure, red color, though this is the ideal “Ruby Red” color that has so much symbolism and popularity spanning across history and cultures.

Anyone who has dealt with a number of rubies will confirm that they are not a single color, but a range. This can make questions like “Is a ruby red or purple?” very confusing for people who are not familiar with the topic.

Basic Composition

For starters, rubies are the red variety of the corundum mineral. Sapphires are the variety of corundum that is any color other than red, which makes them mineralogical cousins. This means that all of these stones are made of the same stuff at the chemical level other than the miniscule percentages of coloring elements.

Most Popular Color

The most popular and expensive varieties are always the rubies that show an ideal red that is not dark, though the other colors are equally brilliant. Often the ideally colored rubies that show best possible color in terms of their hue, tone, and saturation are referred to by trade terms like “pigeon’s blood red”, or more precisely as a “vivid” red.

Hue is what we consider the different colors like red versus purplish red. Tone refers to how light or dark the ruby is, one of the measures for determining a pink sapphire or ruby. The last measure is saturation, which the most inexperienced viewers see as brownish red, or a dull red. The term vivid is usually reserved for colors that we cannot imagine being any brighter or better colored than what they are looking at, although this term is used specifically in reference to saturation. This is why some labs will use trade terms like “pigeon’s blood ruby” on rubies that show ideal quality.

Vivid Red and Pigeon’s Blood Varieties:

First, do not let the carat weight make you think it has anything to do with trade terms. The only reason for the large carat weights is that lab reports are typically only requested for rubies 2 carats and up from vendors, though private requests are a separate story. 

Some lab reports will use trade terms like Pigeon’s Blood, but most of them will only list terms like Vivid Red. This is because “vivid” is not necessarily a trade term, but an indication of high saturation. While many labs will never formally list them on a report, all of them internally note the hue, tone, and saturation for their databases.