January Birthstone Breakdown - Garnet

There are few folks I know who are truly satisfied with their birthstones and I often get complaints from January-born friends that their birthstone feels boring or doesn’t suit them.  Often this dissatisfaction occurs because they only know January’s birthstone, Garnet, as a deep red or brownish red stone, when in fact Garnets come in great variety of hues to inspire even the pickiest January babies.

 Below is a breakdown of January’s birthstone Garnet
to demystify this gem.

Illustration from Science - Hobby Book of Rocks and Minerals (1971)

Carnelian, garnet, quartz, and glazed steatite string of beads from pre-dynastic Egypt ca. 3300-3100 B.C.E. in The Metropolitan Museum of Art collection.

Garnets are Ancient History

Garnets have been used for adornment and abrasives dating back to the Bronze Age and older, including a Garnet necklace that was found in an Egyptian grave dating back to 3800 BCE.

Carved Garnet ring stone from the 1st century B.C.E. “Carved on this almandine garnet is Eros walking to the right and proudly carrying off the weapons of Herakles: the lion's skin, club, bow, and the quiver” on view at The Metropolitan Museum of Art.

There are 6 species of Garnet  

Much like the animal and plant kingdoms, gemstones are broken down into groups, species, and varieties based on their chemical composition and crystal structures. Garnet is a gemstone group consisting of the six predominant species:

Pictured above is a diagram explaining the naming and classification structure of gemstones using Garnets. Diagram was created by The Gemological Institute of America.

Almandine/Almandite

Pyrope

Spessartine/Spessartite

Grossular

Andradite

Uvarovite

Without complicating matters too much, some of the Garnet species can also intermix to create hybrid species like Pyrope-Spessartite and Pyrope-Almandine Garnets.  Fortunately, these species designations are used predominately on the gemology and mineralogy side of things and should not inhibit your ability to get to know Garnet.

Garnets come in every color

 Red is the most common color of Garnet and blue is the rarest color.  You will see orange, green, and purple Garnets used regularly in contemporary jewelry design.

A rainbow of Garnets from Nomad’s.

Garnets are strong 

Garnets measure a 6.5-7.5 on the Mohs scale of hardness.  They are durable for use in jewelry, including rings, though care should be taken with pieces worn daily.

Garnet is Abundant

Red Garnets are one of the most abundantly occurring gemstones on earth.  They are often used as “indicator minerals”; their presence in a location demonstrates to geologists and miners that an area contains the right chemical elements and conditions needed to create other valuable gemstones like diamonds.

Garnet illustrations from Rocks and minerals: a guide to familiar minerals, gems, ores, and rocks (1961).

Garnets You Should Know

 Many different names are used to describe the different colors of Garnet. Some of the ones you may have heard of, like Spessartite or Rhodolite, are the variety names of these gemstones.  Other names you may have heard like Malaya Garnet or Lotus Garnet are descriptive trade names used to sell and market stones and can be helpful in describing color when buying and selling stones.

Rhodolite (Pyrope-Almandine) – A purplish red or pinkish red Garnet typically with a rich saturated color. Rhodolite Garnets tend to be lighter in tone and with a distinct raspberry hue as compared to commercially offered red Garnets, which are typically almandine Garnets.

Purple Garnet (Pyrope-Almandine) – A vivid grape purple Garnet became popular in 2016 when deposits of these stones were found in Mozambique and Tanzania. These luscious gemstones are sometimes called “grape Garnets.”

Rhodolite Garnet rose cut available from Diamondoodles.

Rough and faceted mint green Grossular Garnets and orange Spessartite Garnets from Pala Gems International . Photo by Diamondoodles.

Spessartite (Spessartine) – Orange, but can be brownish, yellow, or reddish orange.  Sometimes called Fanta Garnet, Mandarin Garnet. Deep reddish orange or yellowish orange stones that lean towards brown in hue are often Hessonite Garnets, a Grossular type of Garnet that is also called “cinnamon stone” or referred to as cognac-hued and can be mistaken for deeper, less desirable spessartite Garnets.

Mint Garnet (Grossular) – Also known as Merelani Mint Garnet, named for the region of Tanzania where it was first found, these green Garnets are light bluish green hue as compared to the true green or yellowish green hues of the other green Garnets.   

A horsetail inclusion inside of a Demantoid Garnet from B&B Fine Gems. Photo by Diamondoodles.

Tsavorite (Grossular) – Tsavorite Garnets are a saturated green medium to dark green hue that was discovered in the Tsavo region in Kenya, but is also found in a number of other locations in Africa. Tsavorite Garnets are rare in large sizes and are one of the most expensive varieties of Garnet.

Demantoid (Andradite) – Demantoid Garnets are a vivid green to yellow green color and display strong fire (rainbow flashes).  This is one of the rarest and most valuable varieties of Garnet.  Demantoids can have a unique inclusion of golden fibers that bundle at one end and splay out at the other known as a “horsetail inclusion.”  Unlike most inclusions, the beauty and rarity of horsetail inclusions make them desirable. Demantoids were first discovered in the Ural Mountains in Russia in 1853, but deposits have been found in the 20th and 21st centuries in Africa.

Lotus Garnet from Prima Gems USA.

Malaya/Malaia (Pyrope-Spessartite, Pyrope-Spessartite-Almandine) - These Garnets were first discovered in the 1960s in the Umba River Valley between Kenya and Tanzania. Their color ranges from light to deep peach pink, pink orange, reddish orange, and even to reddish purple. These Garnets were found while looking for Rhodolite Garnet and were originally discarded for being off-color; the name Malaya is derived from the Swahili word for outcast. These gems have become popular in the past five years for their unique blend of Garnet hues.

Lotus Garnet (Pyrope-Spessartite-Almandine) - These Garnets are relatively new to the scene, discovered in 2015 in the Mahenge region of Tanzania. Characterized by their pastel pink and peach hues these Garnets look similar to soft hued Padparadscha Sapphire, Morganite, and Imperial Topaz. Lotus Garnet is a branded trade name for softer colored Garnet from East Africa.

Garnets are phenomenal

 There are two optic phenomena that occur in some Garnets: color change and iridescence.

Rainbow Andradite Garnet seen at the Tucson gem fairs in 2020.

Color change is a phenomenon that occurs when a gemstone is viewed in two different types of light – incandescent and daylight.  This change occurs because different types of light are made up of different colors and wavelengths in turn changing what colors can be reflected from a stone.  There are a few types of Color Change Garnet. Some change color from a purple to magenta, others from pink to a pinkish red, and another variety that change from bluish green to reddish purple similar to the gem alexandrite.  All of these stones are typically referred to as Color Change Garnets.

‘Rainbow’ Andradite Garnets display iridescence. These stones can look a dull brown, but shine with vibrant stripes of rainbow iridescence in the light.  To maximize their iridescent phenomenon, they typically cut into asymmetrical geometric rose cut shapes.  These stones come from Mexico, New Mexico, Nevada, and Japan.