Illinois is full of amazing places to find topaz, and it’s a great spot for gem hunters! Well-known areas like the Kankakee River and hidden spots like Shawnee National Forest are perfect for searching for this beautiful stone in its natural form.

The geology of Illinois makes it an exciting place to search for topaz and other gemstones. Some other great examples are the banks of the Mississippi River and the southern region near Shawnee National Forest, which are great locations to start your hunt.

How Topaz Forms Here

Topaz forms inside hollow spaces in igneous rocks under specific conditions. It grows when high pressure combines with fluorine-rich vapors.

These spaces form as magma cools, leaving room for minerals to crystallize. Over time, the right elements settle, allowing topaz to grow in these gaps.

Topaz often grows alongside quartz and other silicate minerals. This close growth can result in interesting combinations of minerals in one rock.

Topaz is found in areas shaped by volcanic activity and the movement of magma beneath the Earth’s surface. This includes regions where ancient volcanoes once erupted or where magma cooled slowly underground, forming cavities where topaz could grow.

Types of Topaz

Topaz can look different depending on what it’s made of and how it forms. These differences are due to changes in the elements present in the topaz crystals and their environment during their growth.

Imperial Topaz

Imperial topaz is prized for its rich colors, including yellow, pink, and pink-orange. Pink stones are particularly rare. Brazilian imperal topaz often features shades ranging from bright yellow to deep golden brown, with some showing hints of violet.

Some light or brown topaz stones are treated to bring out brighter colors like gold, pink, or violet. However, these enhanced stones may lose their color if exposed to sunlight for too long.

The name “Imperial Topaz” comes from its historical connection to Russian royalty. During the 18th and 19th centuries, this gemstone was reserved for royal use and often featured in their jewelry.

Mystic Topaz

Mystic topaz is a natural gemstone enhanced by a special coating applied to colorless topaz. This thin coating creates a rainbow-like effect on the surface, giving the stone a vibrant, colorful look.

The coating used on mystic topaz is similar to the coating applied to camera lenses. It creates an iridescent effect that shows a mix of bright colors across the stone’s surface.

Although mystic topaz is made from real topaz, its treated surface often causes confusion. The bold colors and shiny appearance come from the added coating, not from the stone itself.

London Blue Topaz

Despite its name, London Blue topaz has no ties to England! The name is simply a marketing term used to describe this popular gemstone.

London Blue topaz is prized for its deep, stormy blue color. This variety is one of the most in-demand types of blue topaz because of its rich and distinctive hue.

The striking blue shades of London Blue topaz are produced through heat treatment, which enhances its natural trace elements. Although topaz is found in many places, most gem-quality stones used for London Blue topaz come from Brazil.

Swiss Blue Topaz

Swiss Blue topaz is known for its bright and vivid blue color, with a light tone and medium saturation.

Because natural blue topaz is quite rare, most Swiss Blue topaz is created by treating clear or pale-colored topaz with radiation and heat. That’s how it gets its vivid color!

Its bright blue shade is also much lighter and happier compared to the darker tones of London Blue topaz.

Blue Topaz

Natural blue topaz is very rare and usually comes in soft, pale blue shades. Because it is so uncommon, most blue topaz available today has been artificially treated to achieve its color.

To make blue topaz, clear or colorless stones are exposed to high-energy radiation and then heated. This method, developed in the 1970s, allows blue topaz to be produced in different shades.

The radiation changes the structure of the crystal, affecting how it reflects and absorbs light. This creates the blue color, making treated blue topaz look very similar to natural blue topaz.

Colorless/White Topaz

Colorless topaz is the most common type found in nature, but small amounts of other elements can give it light blue or golden brown shades. This type of topaz is often treated with heat and radiation to turn it into other colors.

Topaz doesn’t sparkle as much as some other gemstones because of how it bends light. Still, high-quality colorless topaz can shine more than quartz of the same cut and can be polished to a smooth, shiny finish.

When cut in a “brilliant” style, colorless topaz sparkles in different ways depending on the angles. It might have a bright center with duller sides or sparkling sides with a less shiny middle.

Pink Topaz

Pink topaz is a rare type of topaz that gets its color from chromium replacing aluminum in the crystal. This natural process makes pink and red topaz quite rare.

Some pink topaz is made through artificial treatments that change the stone’s color. These treatments help create more pink topaz and make it easier to find in stores.

Pink topaz can be pale or bright, depending on how much it is treated or what natural impurities it contains.

Green Topaz

Green topaz forms naturally but is very rare and costly. Most green topaz sold today is created by treating or coating colorless topaz.

A process called diffusion treatment, which uses chemicals on white topaz, is often used to produce green topaz. Darker green shades usually come from irradiation, similar to how darker blue topaz is made.

Light green topaz, with a color similar to sea green aquamarine, can form naturally but is hard to find. These pale tones differ from the brighter greens created through treatments. 

Bicolor Topaz

Bicolor topaz, also known as polychrome topaz, is a rare natural gemstone found only in the Volyn deposit in Ukraine. These gems display multiple colors in one crystal, often combining shades of blue and gold.

The Volyn deposit is known for its large, high-quality topaz crystals, including these bicolor stones!

What Rough Topaz Looks Like

To find rough topaz in nature, you’ll need to know what it looks like and what its key features are. Knowing these can help you spot the gemstone more quickly and easily.

Crystal Shape

Raw topaz crystals can have different shapes, from long and thin to short and thick. Their ends also vary, often showing blunt, pyramid-like, chisel, or wedge shapes.

Topaz can sometimes appear as chunky pieces, grainy fragments, or smooth, rounded pebbles. It may also form in column-like shapes or mimic the look of feldspar through a process called pseudomorphing.

Hardness

Raw topaz has a hardness of 8 on the Mohs scale, making it tougher than quartz and able to scratch glass. To identify raw topaz, you can test its ability to scratch materials like glass.

However, it can still chip along its natural cleavage planes. It’s still durable but will need to be handled carefully.

Cleavage

Topaz is known for its perfect basal cleavage, which lets it break cleanly along a single flat surface. These smooth, flat surfaces are a defining feature of raw topaz.

This feature is especially clear in rough or broken pieces. It helps set topaz apart from other minerals that may look similar.

Transparency and Glass-Like Luster

Raw topaz is recognized for its glassy, or vitreous, shine, which is most noticeable on freshly broken surfaces. This shiny luster helps set it apart from minerals with dull or resin-like finishes.

Generally, raw topaz can be clear or translucent, adding to its reflective appearance. These qualities together make it easier to identify raw topaz in its natural form.

Color

Raw topaz comes in many colors, including colorless, yellow, brown, blue, orange, and gray. These natural hues are caused by impurities in the crystal structure, giving the stone its variety of shades.

Less common colors include reddish-pink, pink, and green. These rare tones are especially noticeable in unpolished stones.

Tips on Where to look

Finding topaz in nature starts with knowing the right places to look. Certain areas within these state are more likely to have this gemstone in its raw form.

Granite Pegmatites

Search for topaz in areas with granitic pegmatites, where large crystals of feldspar, quartz, and mica are common. These places have the right conditions for topaz to form.

Rhyolites

Look for topaz in volcanic areas with rhyolite, where it can form in cavities within the rock. Focus on spots with visible pockets or cavities that might hold crystals.

Stream Beds and Gravel Deposits

Explore stream beds and gravel deposits near areas known for topaz. Flowing water can break down rocks, carrying topaz crystals downstream and depositing them in sediments.

Hydrothermal Veins

Look in areas with hydrothermal activity, where topaz can form in quartz-rich veins. These veins develop from hot, mineral-filled fluids.

The types of Topaz you can find around the state

In Illinois, the most common types of topaz found are colorless or white topaz, which can sometimes have light blue or golden brown hues. These stones are often treated with heat or radiation to enhance their color and can be found in a variety of shapes, from crystal-like to more rounded forms.

Rare varieties like pink topaz and green topaz can also be discovered, though they are much harder to find in their natural state. Pink topaz, which comes from a natural process involving chromium, is particularly rare, while green topaz is often treated to achieve its vibrant hue.

Some Great Places To Start

These are some of the places where you can find topaz around the state.

Fayville area streambeds

The Fayville area is a great spot for finding diamonds, thanks to its rich geological history. The streambeds here have exposed older layers of sediment that may hold rough diamonds and other gems.

To increase the chances of success, focus on the gravel beds where materials collect along the streams. Using a small shovel or sifting screen can help separate stones, and keep an eye out for clear, shiny stones with angular shapes, which could be diamonds.

Thebes gravel pits

Thebes gravel pits in Illinois are a hidden gem for diamond hunters, offering a promising location to find rough diamonds. Over time, the area has been shaped by erosion, which has exposed layers of sediment rich in minerals and gemstones.

For the best chance to find diamonds, focus on the gravel deposits found throughout the pits. Be sure to look for shiny, angular stones that could be diamonds among the other gravel and minerals.

Palestine stream deposits

The Palestine stream deposits in Crawford County, Illinois, are known for producing topaz and other gemstones. Streams and gravel beds in this area contain stones brought to the surface by erosion, making it a great spot for gem hunters.

Look for topaz in slower-moving parts of the stream, where heavier stones settle. Use tools like a fine mesh sieve and a small shovel, and search during early morning or late afternoon for the best light.

West Frankfort area

The West Frankfort area in Illinois is known for its rich geology, making it a great place to search for diamonds. The land has been shaped by years of erosion, exposing layers of sediment that may hold hidden gemstones, including rough diamonds.

Focus on areas near streambeds or old mining sites, as these spots are where materials are more likely to be exposed. Look for stones that stand out with a clear, shiny appearance or angular shapes.

Saline River deposits

The Saline River deposits in Illinois are a great place to look for diamonds due to erosion that has brought hidden materials to the surface. The river has moved layers of sediment, which might contain rough diamonds among the gravel and debris.

When exploring the area, focus on gravel bars and streambeds where materials tend to collect. Look carefully for clear, shiny, or angular stones, as they could be diamonds mixed with other minerals.

Places Topaz has been found by county

Other places in the state are good for looking for topaz. These areas have different types of landscapes but still offer the chance to find some great gems.