Black Prince's Ruby: Spinel in Imperial State Crown

The Stone That Isn't a Ruby

Set in the front cross of the Imperial State Crown, directly above the Second Star of Africa diamond, is one of the most historically significant — and most misnamed — gemstones in the world. The Black Prince's Ruby is not, in fact, a ruby. It is a red spinel — a different mineral species entirely — that was indistinguishable from ruby by the gemological knowledge available before the 19th century. This distinction, far from diminishing the stone's significance, adds another layer of fascination to an already extraordinary history.

The Black Prince's Ruby is a large, irregular cabochon of deep red spinel, approximately 170 carats in its rough form and now polished to a smooth, rounded surface that displays the stone's rich color to maximum effect. A small ruby has been set into a hole drilled through the stone — a later addition that may have been intended to repair damage or to add a genuine ruby to a stone that was increasingly recognized as something else.

Ruby vs. Spinel: Understanding the Difference

Ruby and red spinel are both red gemstones that form in similar geological environments, and for most of human history they were considered the same stone. Both are found in the gem gravels of Myanmar (Burma), Sri Lanka, and other Asian sources; both display vivid red colors; and both have similar hardness and luster. The distinction between them — ruby is corundum (aluminum oxide) while spinel is magnesium aluminum oxide — was only established with the development of modern mineralogy in the 19th century.

Many of the most famous "rubies" in history have turned out to be spinels upon modern examination. The Timur Ruby (another stone in the British royal collection) is also a spinel. The "ruby" in the Russian Imperial Crown is a spinel. The distinction matters gemologically — fine rubies are generally more valuable than fine spinels of comparable size — but historically, the two stones carried identical symbolic associations and healing properties.

In contemporary crystal healing, red spinel is recognized as a powerful stone in its own right — associated with renewal, revitalization, and the energizing power of red. Its properties of vitality, courage, and protection align closely with those of ruby, reflecting the shared energetic signature of these two red stones.

The Stone's Medieval Origins

The earliest documented history of the Black Prince's Ruby places it in the treasury of Abu Said, the Moorish King of Granada, in the 14th century. In 1367, Pedro the Cruel of Castile — who had seized the stone from Abu Said after murdering him — gave it to Edward the Black Prince (son of King Edward III of England) as payment for military assistance at the Battle of Nájera in Spain.

Edward the Black Prince — one of the most celebrated warriors of the medieval period, famous for his victories at Crécy and Poitiers — was an appropriate recipient for a stone associated with courage and military prowess. The stone passed to his son, who became Richard II, and has remained in the English royal collection ever since — a continuous association of nearly 660 years.

Agincourt: The Stone's Most Famous Moment

The Black Prince's Ruby's most famous historical moment came at the Battle of Agincourt on 25 October 1415, when Henry V of England led his outnumbered army to a stunning victory over the French. According to tradition, Henry wore the stone set in his battle helmet — and during the battle, the Duke of Alencon struck Henry's helmet with such force that a fleur-de-lis was knocked from the crown, but the stone survived.

This story — whether entirely accurate or embellished by later tradition — captures the stone's association with royal courage and divine protection in battle. A king who wore the Black Prince's Ruby into battle and survived was understood to be under the protection of the stone's power — a living demonstration of the protective properties attributed to red stones in medieval gemstone lore.

The Stone Through the Centuries

The Black Prince's Ruby has survived some of the most turbulent episodes in English history. It survived the Wars of the Roses, the Tudor succession crises, and the English Civil War. When Parliament ordered the destruction of the Crown Jewels in 1649, the stone was sold — but it was subsequently recovered and returned to the royal collection at the Restoration of Charles II in 1660.

The stone was set in the Imperial State Crown made for Queen Victoria in 1838 and has remained in the crown ever since, occupying the most prominent position — the front cross, directly at eye level when the crown is worn — that reflects its status as the most historically significant stone in the collection.

Healing Properties: Red Spinel and Ruby

The Black Prince's Ruby — whether understood as spinel or ruby — carries powerful healing and protective properties that have been recognized across cultures and centuries. Red stones are universally associated with vitality, courage, and the life force — the blood-like color connecting them to the energy that animates living beings.

In contemporary crystal healing, red spinel is used to revitalize depleted energy, restore enthusiasm and motivation, and provide protection during challenging periods. It is associated with the root chakra — the energy center governing survival, vitality, and the will to live — and is recommended for those who feel exhausted, discouraged, or under threat.

Ruby, with which the Black Prince's Ruby was historically identified, carries similar properties with additional associations: passion, leadership, the courage to pursue one's highest purpose. The stone's centuries of association with English military victory and royal courage have given it an accumulated energy that amplifies these inherent properties.

A Stone for the Ages

The Black Prince's Ruby has been part of the English royal collection for nearly 660 years — longer than any other stone in the Crown Jewels. It has witnessed the rise and fall of dynasties, the transformation of England into Britain and Britain into a global empire, and the evolution of the monarchy from absolute power to constitutional symbol. Through all of this, it has remained in its place — a constant red presence at the heart of the English crown, carrying its accumulated history and its enduring healing power into each new era.