JULY BIRTHSTONE HISTORY: The End of Black Birthstones

July birthstone used to be the only black gem of the 12 month stones. However, the original birthstone for July lost its place to a glassy red gem from India. Now, in addition to January’s garnet and August’s spinel, July houses yet another red birthstone.



You shall make a breastplate of judgment. … You shall set in it settings of stones in four rows: a row of sard, peridot and emerald shall be the first row; and the second row a garnet, a lapis lazuli and an onyx …

— Exodus 28:15-18

Onyx was the July birthstone from Aaron’s breastplate in Exodus. Known as yahalom in Hebrew1 and onychion in Greek,2 onyx accordingly became July gemstone in Jewish culture, Rome, Italy and Spain. By the advent of the 15th century, Europe in general honored onyx as the birthstone of July. Onyx held its position until 1912, when America replaced this July stone with ruby.3

The name onyx meant “fingernail,” in reference to the gemstone’s white bands resembling the tip of a fingernail. The onyx of the ancients referred to stones of various colors — most notably yellow, red and green — so long as they have this white band.4 The banded black variety then known as Arabian onyx has come to define what onyx is commonly thought of today. Still, today’s most popular onyx displays no band at all, just a plain black.

Onyx is a variety of chalcedony, the opaque or translucent form of quartz. Unlike agate, onyx displays relatively consistent, parallel bands.


The foundations of the city’s wall were adorned with all kinds of precious stones. The first foundation was jasper; the second, lapis lazuli … the fifth, sardonyx …

— Revelation 21:19-20

Sardonyx is the July birthstone from the Book of Revelation. While onyx is the name of the gem on Aaron’s breastplate, Revelation specifies sardonyx, an onyx with red bands, as the corresponding Foundation Stone. Described as the 5th Foundation Stone, sardonyx accordingly went to the 5th sign of the zodiac, Leo, and the partially concurrent month of July. The Russians in particular recognized sardonyx as birthstone for July alongside ruby.

As the name suggests, sardonyx is a variety of onyx striped with bands of sard, which is red in color. While red-and-white banding is its popular pattern, sardonyx may also have black bands.

The ancients favored sardonyx over black onyx, not least out of fear over the latter’s power. They recommend that any onyx jewelry goes with sard.5 Sardonyx is a convenient combination of sard and onyx, and harmoniously mixes the powers of both gems.

From Humanfeather, CC BY 3.0


Ruby rose to popularity as July birthstone thanks to Ancient India. The Hindu birthstone for the zodiac sign Leo, ruby is the gem of the Sun in India. The Hindu’s love for ruby shows in their designation of the gem as the sole birthstone for 2 months: July and December.

Other cultures echoed India’s appreciation of ruby, but picked only 1 month for the gem. While the Arabs, Jews, Rome, Italy and Spain honored ruby in December, Poland and Russia made ruby the July birthstone.

From the 1400s to early 1900s, Europe in general acknowledged ruby not in July, but in ruby’s other month. This 4-century-old convention, however, was reversed in 1912, when America’s jewelers declared ruby as the sole July birthstone.3

Ruby is the red variety of corundum, which in a different color would be called sapphire. Due to its beautiful red color and extreme rarity, ruby commands an immensely high price. Ruby’s value is determined mostly by its color. The richer the red of ruby is, the more expensive is the stone. The most excellent color is described as “pigeon-blood red,” in reference to the brilliant red color of a pigeon’s blood spilled against white feathers.


The Arabs designated carnelian as birthstone for July. To an extent, this choice is consistent with Hebrew tradition, since the red bands on the original July birthstone, sardonyx, is the same stone as carnelian, also known as sard. Europe, however, rejected the Arabian designation for carnelian in favor of the original July gemstone, onyx, as well as turquoise. Worse, in 1912, at America’s decision, not a single month in the calendar had carnelian for its birthstone.3 Nevertheless, carnelian managed to find redemption with the dominance of ruby. Britain added carnelian as alternate July stone to the red corundum.6

Carnelian makes a good alternative to ruby on account of its color, which is also red, although the color draws toward orange. Carnelian is the translucent red variety of chalcedony.


The 1400s saw Europe make turquoise a July birthstone alongside onyx. Turquoise debuted as December gem in Poland and Russia. Turquoise was one of 2 gems — the other being ruby — that vied to replace the obscure original birthstone of December, ligure. In the 15th century, Europe kept ruby in December, and threw turquoise to the other month where ruby had been assigned, July. Turquoise remained a birthstone for July until 1912, where America transferred the gem back to the last month of the calendar.3

Turquoise is a valuable opaque stone ranging in shade from pale green to light blue.

Black Onyx Necklace

Red July Birthstone

In with the red, out with the black, was the conclusion of July gemstone. The original birthstone for July, onyx, was most popular in black. Black was indeed the July birthstone color. However, people seemed less taken with black gemstones, and much more interested in the fiery-red gem. With the ouster of onyx came the symbolic end of black gemstones among the natal stones, which in contrast currently include not 1, not 2, but 3 red gems across 3 different months. January’s garnet and August’s spinel are glassy red gems similar to July’s ruby.

Know Their Magic

Each birthstone for July is attributed with magical properties. Know the magical powers of July stone, as well as those of your zodiac birthstones, when you read my book Power Birthstone.

Learn the magic of July Birthstone



“Exodus 28.” The Bible. Bible Hub, biblehub.com/interlinear/exodus/28.htm. Accessed 28 July 2019.


“Exodus 28.” Septuagint. Blue Letter Bible, www.blueletterbible.org/lxx/exo/28/1/s_78001. Accessed 28 July 2019.


Knuth, Bruce G. “Birthstones.” Gems in Myth, Legend and Lore. Revised ed. Parachute: Jewelers Press, 2007. pp. 293-327.


Pliny. “Book 37 – XXIV.” Natural History. Trans. D. E. Eichholz. Loeb Classical Library ed. Vol. X. Harvard University Press, 1962. Wikisource, en.wikisource.org/wiki/Natural_History_(Rackham,_Jones,_%26_Eichholz)/Book_37. Accessed 27 July 2019.


Knuth, Bruce G. “Onyx.” Gems in Myth, Legend and Lore. Revised ed. Parachute: Jewelers Press, 2007. pp. 151-152.


“Birthstones.” The National Association of Goldsmiths. Internet Archive, web.archive.org/web/20070528103836/http://www.jewellers-online.org/pages/tips.php?id=2&idnew=2. Accessed 30 July 2019.

Published October 17, 2019