Buying agate – here’s what you need to know

Interested in buying agate but don’t know much about it? Then you’ve come to the right place! Agate is a gorgeous gemstone that, in the hands of expert designers, can turn into classy and elegant jewelry. It is affordable and comes in a range of colors and natural designs. Because of the wide variety of agates available, you are bound to find a piece of agate that will be exactly what you are looking for. In this shopping guide, we’ll walk you through everything you need to know about agate to help you make the right decisions and ask the right questions before you purchase.

What exactly is agate, this banded rock?

Colorful agate stones

Agate is a variety of chalcedony, which is a microcrystalline form of quartz. Microcrystalline means that the rock structure is made up of fine and minute crystals (often only visible under a powerful microscope). Not all agate qualify as a semi-precious stone. It has to be of a certain quality and color. Agate is found everywhere in the world but most notably in Brazil, Uruguay and Mexico.

So how exactly does agate form? This is the process whereby silica is deposited within pockets of igneous rocks. The agate forms either around the walls of the pocket, forming concentric layers, or in layers starting from the bottom up. As each new wave of silica deposit is brought in from groundwater, these packed layers continue to grow, creating the banded patterns that easily distinguish agate from other stones.

Because of the way it is formed, each piece of agate is different from the other, making the stone you buy distinctly yours. This is one main reason that makes agate so perfect for jewelry. No one else will have an identical piece, making yours unique. Agate is one of the oldest gemstones used in jewelry. In fact, small agate beads have been found in the Middle East, and are thought to be approximately 9000 years old!

What type should I buy?

As you probably already know, agate comes in many forms. These varieties occur due to the composition of the stone and are distinguished mainly based on color and inclusions. It would take a whole article just to list and explain each type of agate so I’ve only listed some of the most popular varieties below.

Agates with unique inclusions

Dendritic Agate

This is not the typical type of agate. It does not have a banded pattern but instead is mostly colorless or white or gray, with brown/black diverging inclusions. Dendritic agate is sometimes called tree agate because its interesting inclusions are dendritic, which means having a branched form like a tree. If you’re willing to fork out a little bit more money for it (it is a pricier variety of agate), it is well worth it due to its unique and intriguing look.

Moss AgateMoss agate ring

What sets moss agate apart is its noticeable impurities. It does not contain bands as typical agates do and is similar to the dendritic variety in this respect. Moss agate is a white stone with greenish inclusions, suggestive of moss (hence the name).

Plume Agate

This form of agate has feather-like inclusions, mainly on the surface, suggestive of ferns or other fauna present on the walls of the rock cavity during formation. When polished and properly cut, these inclusions blend in beautifully with the stone, creating dazzling designs and stunning colors.

Agates with stunning colors and patterns

Fortification AgateFortification agate pendant

This is the most common type and generally the one that springs to mind when we talk about agates. This variety has the famous crystallized bands that follows the contours of the cavity, and when sliced, looks much like a colorful cross-section of an old tree, full of rings.

Fire Agate

This beautiful and rare variety of agate comes with an iridescence that sets it apart. Fire agates are old stones, formed many millions of years ago through volcanic explosions. The stone itself looks fiery due to its reddish-brown color often combined with little shots or swirls of color. It is a valuable stone and can come with a premium.

Lace Agate

As the name suggests, this variety is reminiscent of beautiful lace with elaborate hoops and swirls. It is among the rarest and most highly coveted forms of agate. You can find these in many colors, with red and blue being quite rare.

The ins and outs of agate - knowing the 4Cs

ColorBlue and red agate bracelets

Agate (like most other gemstones) comes in a variety of colors, such as red, yellow, pink, blue, orange, black, gray, rainbow (multi-colored) and even banded. These last two varieties come with a combination of colors, where the colors can either be all combined together in one rock or separately layered, row after row. 

The color you choose depends on your preference. Due to the porous nature of agate, most of the gemstones are dyed to enhance the look.

Cut

Agate can be found in many shapes, including round, pear, square and emerald. If agate is cut expertly, it will enhance the natural bands of the stone. It should also be cut to suit the piece of jewelry that it is going to be made into, to bring out its best color and appearance.

Clarity

Clarity is a critical factor when choosing agate. Crystal clear agate with no noticeable inclusion is very valuable. Make sure that the stone is eye clean and does not contain cracks or scratches.

However, with some varieties of agate such as moss, dendritic and plume, it is the inclusions that enhance the value. These can be relatively more expensive and are highly coveted due to their unique nature.

Carat

Agate can be found in large and substantial form naturally. Large agate slices are used to make stunning furniture, such as tables as well as various crafts.  The images below, taken from Amazon, show decorative little tables and coasters made of agate slices.Agate table

Blue agate coasters

In the process of creating agate gemstones, the rough agate is sliced and polished to form smaller stones of varying carats. Generally, agates between 2-4 carats are suitable for jewelry, while sizes over 4 carats are generally used for crafting ornamental items.

Prices of colored agates are calculated per carat as agates are sold by weight. Similar sized stones of different varieties vary largely in value, so it's important to know the variety that you are buying.

Agate in Jewelry

Agate is a stylish and elegant stone that goes beautifully with any outfit. Famous designers such as Chanel and Yves Saint Laurent have used agate in their designs, and celebrities often sport the bright colored stone. Time and time again, agate will pop up in the fashion scene as the ‘in’ thing. So, how should you wear agate jewelry? Let’s find out!

Agate necklacesAgate necklace

Because agate is an eye-catching stone, an agate necklace can really add color and style to your overall look.  You can go two ways about this.

  1. You can opt for a minimalist style, choosing a delicate and classy agate pendant on a chain. It goes well with formal and casual wear.
  2. If you are someone who likes to make a statement, consider a chunky agate necklace. This will add color to your outfit and take it up to the next level of glamor.

Agate bracelets and cuffs

For a simple, sweet look, agate bead bracelets will add a pop of color to your overall look. These are easy to find and come in many colors.

If you are after a glamorous look for an evening function, consider an agate cuff. It is eye-catching and stylish, immediately upgrading your overall look. Again, the color you choose depends on your outfit, although blue and pink agates are quite popular colors.

Agate earrings and ringscoctail agate ring

Agate earrings are simple and classical, great for a day or evening look. Choose a dainty beaded pair or dangle earrings. The agate-slice dangles are extremely popular and stand out.

Agate rings are a great choice for both men and women, especially for cocktail rings. Because agate is an affordable stone, they work beautifully in such rings, making a bold statement of confidence and style.  You can also find great vintage designs for agate rings. Due to its natural antique look, many jewelry designers of the past, especially Art Nouveau, used agate for vintage rings.

Imitations and Enhancement of Agate

Because agates are quite affordable and found in abundance, you will not often find an imitation on the market. Sometimes glass can be sold as agate, so you will need to watch out for that. For example, you could be paying a large sum for a superior fire agate which may very well be a piece of well-crafted glass. Also make sure that you aren’t being sold a poor quality agate for the price of a valuable one.  This is why it’s best to check the reputation of the jeweler you intend to buy from to make sure you aren’t being ripped off.

In terms of enhancement, as agates are porous, they are often dyed to enhance their natural color. Generally, apart from lace agate, most of the other varieties are dyed. Enhanced stones don’t require any special care. When purchasing agate, the jeweler should inform you whether or not the stone has been dyed, and generally these stones are labeled with a ‘D’ for this purpose. A good way to find out is by putting the stone into a sealed plastic bag and near heat, such as sunlight. When the stone heats up, it will exude some dye if it is indeed a dyed stone.

How to care for your agate

Agate is a durable stone with a Mohs hardness rating of 6.5 to 7. This means that only materials over this rating can scratch or damage the stone. It is best to store your agate in a cloth pouch, away from direct sunlight to prevent any damage, especially discoloration. Because most agates are dyed to enhance its natural color, take extra care when cleaning the stone. Use mild soapy water to clean agate jewelry but avoid using harsh chemicals or ultra-sonic cleaners.