Agate Properties, Meaning, Facts and Photos

What is Agate?

Agate is a translucent variety of chalcedony made up almost entirely of silicon dioxide.

Agate is often black, white or grey but can also be exceptionally colourful. The colour and banding in agate come from impurities of other minerals.

Quartz crystals in agate are colourless in their purest form but turn red or brown with the presence of iron. With manganese, the crystals turn pink, and with chromium, a shade of green.

The type of agate that's easiest to identify usually has distinctive bands. Some argue a stone must exhibit banding to be classified as a 'true agate'. However, several types of agate are not banded.

Over the years, many discussions have taken place regarding using trade names. From a geological perspective, they're often inaccurate and misleading.

Moss and dendritic agate do not exhibit visible banding but feature inclusions known as dendrites. Often mistaken for organic matter, dendrites are crystal formations similar to those seen on glass during winter.

The word dendrite comes from the Greek for 'tree' and refers to a 'branching form'.

Although frequently found within igneous rocks, agate can also occur in other rock types. Its formation, which is exceptionally complex, begins when groundwater containing silica (sand or quartz) that enters the rock through holes dries up, leaving behind a residue of minerals.

As the process repeats, multiple layers of minerals build up within the rock following the outline of the cavity.

Once full, the mass begins to crystallise.  Quartz crystals often grow in space that has not been filled.

The cavity containing the crystallised minerals is known as a nodule. Depending on the type of rock, it can be incredibly resilient to weathering. It's not unusual for the nodule to survive long after the host rock has eroded.

The agate formation remains locked away until the nodule is found and broken open.

On the Mohs scale of mineral hardness, agate grades 7. Being relatively hard makes it an easier stone to work with.

The History of Agate

The history of agate can be traced back more than 2000 years to the writings of ancient Greek philosopher Theophrastus [c.370-285 BC].

The process of describing different types of agate and their properties and meanings can be found in his works, Theophrastus On Stones.

In this reference, he compares the hardness of agate to onyx and discusses how one type of agate differs from the other because of "its irregular and uncertain manner of spots, clouds and variegations".

He says although agate stones are predominantly grey, different colours can be present and are often beautifully spread out. Patterns may resemble trees, shrubs, plants, clouds, rivers and even animals.

He goes on to say, "the ancients" organised agates into different types.  Each one was given a name that highlighted its difference from the "common agate". That difference could be colour, markings or texture.Red agate was known as haemachates. The prefix 'haema' comes from the Greek for 'blood', which refers to the stone's colour. The name 'achates' came from the river in Sicily where agate was discovered.

Regarding its discovery, Theophrastus wrote that these stones have been "found to exist in almost every nation on Earth." Those with patterns resembling trees and shrubs were called dendrachates (from dendrite), whilst other types were "idly named" according to the powers they held or because of their similarity to animal skin.

The ancient Roman author Pliny the Elder also wrote about the properties and meaning of agate in his works 'Naturalis Historia'.

Pliny wrote;

"Achates was a stone formerly in high esteem, but now held in none. It was first found in Sicily, near a river of that name; but has since been discovered in numerous other localities. In size it exceeds any other stones of this class, and the varieties of it are numerous, the name varying accordingly."
 

He goes on to name several types of agate and explains where they can be found. Like Theophrastus, Pliny also makes reference to dendrachates (dendritic agate) which he says is "marked with small shrubs."

He discusses the meaning of different types of agate from India and their distinctive markings and says, "The sight of some is beneficial for the eyes whilst others when held in the mouth allay thirst. Then there are those which are good for counteracting the effects of poison inflicted by the scorpion. Agate stone can also be found in Cyprus."

Pliny believed those with uniform colour would render athletes invincible and said agate with the highest value has the transparency of glass.

Agate, one of the oldest minerals, was highly valued by many ancient cultures, including the Sumerians, Egyptians, Greeks, and Romans. It was widely used for talismans, seals, vessels (containers for liquids), beads and gemstones. 

Different Types of Agate

Agate stones are typically characterised by concentric, curved or angular banding. They can also exhibit other curious and intricate patterns.

Hundreds of different types of agate can be found around the world, and many have been given trade names. These often indicate the locality where a stone is found or a particular colour or characteristic.

Fortification agate is a generic name for stones whose bands are arranged at sharp angles. The name stems from the shape, which was once believed to resemble the lines of a fortress. A fortification is a defensive wall or reinforcement built to strengthen a building against attack.

Blue lace agate and crazy lace agate are both types of fortification agate.

Botswana Agate comes from Botswana, Brazil Agate from Brazil and fire agate exhibits a distinctive flash of colour caused by interference and diffraction of light in thin layers of silica and iron oxide.

Polka Dot Agate is often but not always spotted.

More Agate Facts

An agate was believed to have been the second stone in the third row of the high priest breastplate. This religious garment from biblical times was adorned with twelve gemstones. It was worn by the Jewish high priest whilst presenting himself to God.

Agate's colour is dependent on the presence of other minerals. Black, white and grey agate stones are often dyed to make them more appealing. 

The practice of dying rocks and minerals can be traced back thousands of years.

Despite everything that has been learned about the formation of agate, so much is still not fully understood. Its formation has never been studied from start to finish in real time. Nor has it been possible to recreate agate in a laboratory setting.  Therefore, much of what is known about this mineral is supposition.

Healing Properties of Agate

Agate is a powerful grounding stone that stabilises energy and balances yin and yang.

Being grounded means being well connected with Earth and our surroundings. That helps us to remain calm and rational and make better decisions, especially when surrounded by chaos.

Known as the stone of balance and harmony, agate is widely used for its ability to bring emotional healing to mind, body, and spirit.

It makes sense of the madness that we deal with in everyday life.

Agate can bring information deeply rooted in the subconscious to the surface and rebuild self-confidence.

Its soothing energies can help with turmoil, frustration and anger, allowing the healing process to begin. Agate works at its own pace but is powerful yet gentle. It’s associated with stamina, courage, vitality and strength.

When used in meditation, agate promotes deep inner peace and tranquillity. It creates a space for introspection and self-reflection. Introspection allows you to understand yourself, while self-reflection lets you process what you learn.

Agate's healing properties help you navigate life's challenges with eloquence and grace. It enhances focus, clarity, perception and analytical skills.

Agate is an important companion for those on a journey of self-discovery and holistic well-being. It's associated with the star sign Gemini. According to the Traditional and Ayurvedic Birthstone Charts, agate is May's birthstone.

On the Mystical Chart, agate is the birthstone for September.

Article Pictures

The first picture in our article is courtesy of Captain Tenneal. The second (dendritic inclusions in agate), fifth (crazy lace agate) and last picture are courtesy of Stan Celestian.

The agates in the museum display are in the Smithsonian Museum of Natural History Washington D.C. Photo by Stone Mania.

The fourth picture (dendritic agate) is courtesy of Steve Blyskal.

Most are clickable and redirect to the original image.

Pop-up photos: Blue lace agate - Stone Mania. Fortification agate - Courtesy of Steve Blyskal. Fairburn agate, fire agate - Courtesy of Captain Tenneal. Botswana agate - Courtesy of Stan Celestian.