Ruby is one of the oldest known minerals in the world. Its English name is derived from the Latin word “ruber” which means “red.” It is also the historical gemstone of July. Only one other stone was widely considered July’s birthstone: onyx. Although not as prestigious as the ruby crystal, the onyx stone is great in its own right. Let us examine the history of the ruby as a birthstone and see how it remained in its position, unlike so many stones in other months.


Ruby’s association with heat, fire, and summer is practically universal. Even the navaratna lists ruby as the sun’s gemstone. Fire is warm and the color red is often associated with heat and fire. The connection is self-evident. Like other major gemstones, medieval philosophers associated them with both religious and secular values. The most common value that fell into both camps was that of love. A ruby crystal, in short, was held in high regard. But what about for birth stones?

According to Kunz, however, there were only a couple of cultures that accepted ruby as the stone of July: the Polish and the Russian. Still, he claims that Arabs designated carnelian as the stone of July. It would appear that the stone of July has to be red, right? Not entirely.

Kunz lists the onyx stone as the historical stone for July. How did a black stone end up as the stone of July for so many cultures across different eras? The answer is not easy to obtain.

Image of Ruby Kyanite Terminated Point

Let us talk colors first. One of the reasons why ruby was probably chosen to be July’s stone is due to its color and how it can symbolically represent something. In medieval art, black represented death, sin, devilry, and hell. This is why many older depictions of Satan are not red as we see today but pitch-black. While hell is hot, it is probably not why onyx was seen as a July stone. However, some of onyx’s color is on a positive note. For instance, in the mid-17th treatise Gemmarius Fidelius, the author writes, “the onyx is a pretious [sic] gemme which represents the candour and beautie of mans nayl.”

Thomas Nicols is referring to fingernails. This is further reinforced by the fact that we draw the word “onyx” from the Greek spelling which translates to claw, talon, or fingernail. Although onyx is usually black, it can have white streaks, and these streaks are most likely the white color of “mans nayl” that he is describing.

It is also possible that the color symbolism of onyx was overshadowed by religion and scarcity. Another reason why ruby was chosen was due to its rarity and high quality. Likewise, onyx is one of the most frequently named minerals in the Bible, and it is not a common stone (especially high quality pieces). It was used often in cameos and intaglios (see the famous Gemma Augaustae).

There is another birthstone in July not yet discussed. It is also the birthstone of another month in present times. Can you guess what it is? Believe it or not, it is sapphire.

This was probably not a popular idea. It appears in the same article of the “Jewelers’ Circular” that lists emerald as June’s stone. Nonetheless, it deserves to be mentioned if only for it standing out as the oddball birthstone list.

According to Kunz, ruby was not always July’s birthstone. In fact, it was December’s birthstone.


Ruby’s rarity, color symbolism, and religious significance all likely molded it into being the perfect stone of July. Likewise, Onyx, although not accepted today as a birthstone in general, may have enjoyed popularity due to its rarity and aesthetic beauty.

Image of Ruby Ring with Diamonds


Augustyn, Allison, and Grande, Lance. Gems and Gemstones: Timeless Natural Beauty of the Mineral World. United Kingdom, University of Chicago Press, 2009.

Barry, Fabio. Painting in Stone: Architecture and the Poetics of Marble from Antiquity to the Enlightenment. United Kingdom, Yale University Press, 2020.

Bertonasco, Marc F., and Norden, Linda Van. Crashaw and the Baroque. United Kingdom, University of Alabama Press, 1971.

Guenzi, Caterina. Words of Destiny: Practicing Astrology in North India. United States, State University of New York Press, 2021.

The Grove Encyclopedia of Medieval Art and Architecture. United Kingdom, Oxford University Press, 2012.

Harriman, Tenn. “Queries by Circular Readers.” The Jewelers’ Circular, vol. 34, no. 1, Feb 3, 1897.

Kunz, George Frederick. The Curious Lore of Precious Stones. United Kingdom, Lippincott, 1913.

Nicols, Thomas. Gemmarius fidelius, or the Faithful Lapidary. United Kingdom, H. Marsh, 1659.

Russell, Jeffrey Burton. Witchcraft in the Middle Ages. Ithaca, Cornell University Press, 1972.

Woolgar, Christopher Michael, and Woolgar, C. M. The senses in late medieval England. United Kingdom, Yale University Press, 2006.

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