People do find garnets in South Dakota, often while looking for something else. These stones are usually tucked into deposits where denser minerals accumulate over time.

The signs can be subtle, especially when garnets are mixed with other dark or glassy material. Color and weight offer clues if you know how to read the mix.

It doesn’t take advanced tools to spot them, just patience and a sharp eye for contrasts in washed gravel. Some of the most overlooked material hides the best finds.

There’s still a lot to discover, but knowing where to start can save hours of searching and keep you from wasting time in the wrong places.

How Garnet Forms Here

Garnet forms deep underground when rocks get squeezed and heated during metamorphism. Think of it like baking cookies – but instead of dough, you’ve got minerals like aluminum, iron, and silica getting cooked under intense pressure.

When these minerals reach temperatures around 400-700°C, they start rearranging their atoms into garnet’s distinctive crystal structure.

What’s cool is that garnets often grow by pushing other minerals out of the way! That’s why they form those perfect geometric shapes.

Most garnets need high pressure too, which is why they’re usually found in rocks that were once buried miles beneath the surface. The slower they grow, the bigger and clearer they become – some taking millions of years to reach their full size.

Types of Garnets

Garnets are captivating gemstones that showcase an impressive range of colors and varieties, each determined by their unique chemical composition. Understanding these differences helps in identifying the stone’s value.

Almandine Garnet

Almandine garnet stands out with its rich, deep red to reddish-brown color. The stone sometimes shows hints of orange or brown, making each piece unique. Its color intensity remains consistent throughout the stone, creating a beautiful depth that catches the eye.

The crystal structure of almandine follows a perfect cubic pattern, forming well-defined shapes with smooth faces. This symmetry contributes to its striking appearance and helps light bounce through the stone evenly.

What makes almandine special is its high iron content, which gives it a higher specific gravity than other garnets. This means it feels slightly heavier in your hand compared to similar-sized stones. Its refractive index of 1.74 to 1.83 creates excellent brilliance and fire.

Most almandine garnets are remarkably clear, though some may contain natural inclusions that create interesting patterns. These patterns can add character to the stone without affecting its overall beauty or durability.

Pyrope Garnet

Pyrope garnet captivates with its intense red-to-purplish-red color. The color is so pure and vibrant that some specimens have earned the nickname “Cape Ruby.”

This stone has excellent clarity, rarely showing visible inclusions. When present, some inclusions can create a fascinating star effect called asterism, where a six-pointed star seems to float on the surface.

The stone appears especially vivid when cut into clean, geometric shapes that maximize light return.

Some pyropes show a subtle color shift, appearing slightly different under natural and artificial light. This subtle change adds to their charm and makes each stone unique.

Their exceptional clarity and lack of internal flaws make them particularly appealing to collectors.

Spessartine Garnet

Spessartine garnet showcases a stunning range of orange colors, from bright mandarin to deep reddish-orange. The most valued pieces display a pure, vivid orange. This distinctive coloring comes from manganese in its chemical makeup.

When cut properly, spessartine exhibits bright flashes of light and exceptional sparkle. Some stones show a subtle “sugar-like” texture that creates a soft, internal glow.

Pure spessartine is rare in nature, making high-quality specimens particularly valuable. Most stones contain trace elements that create subtle color variations.

The stone’s transparency ranges from completely clear to slightly cloudy. Clear specimens are highly prized, but some collectors prefer stones with slight cloudiness that creates an interesting depth effect.

Andradite Garnet

Andradite garnet displays the widest color range of all garnets. Colors span from bright green to yellow, brown, and black. The green variety, known as demantoid, is particularly treasured for its brilliant, emerald-like color and exceptional sparkle.

This stone has the highest dispersion rate of all garnets, even higher than diamond. This means it breaks light into rainbow colors more effectively, creating fascinating fire and brilliance.

Some andradite garnets contain unique internal features called “horsetail” inclusions. These fine, needle-like patterns are actually desired by collectors and add to the stone’s value.

The stone’s surface has a bright, glass-like luster that enhances its natural beauty. Some specimens exhibit unique optical features such as asterism (star-like patterns) and chatoyancy (cat’s eye effect), which further enhance their visual appeal.

Grossular Garnet

Grossular garnet comes in an amazing range of colors – from green and yellow to pink, orange, and even colorless. The most striking feature is the presence of internal swirls and streaks that create unique patterns within each stone.

The stone’s surface has exceptional brilliance that rivals expensive gems like emeralds. Light bounces through it beautifully, creating bright flashes and sparkles.

A special variety called Mint Garnet glows under ultraviolet light, creating an otherworldly effect. This unusual property makes it particularly interesting to collectors. The stone’s clarity is typically excellent, with few visible impurities.

The presence of trace elements like chromium and vanadium creates its varied colors. These elements mix in different amounts, resulting in subtle color variations that make each stone unique.

Some pieces show color zoning, where different shades blend together in distinct patterns.

Uvarovite Garnet

Uvarovite garnet displays a striking emerald-green color that remains consistent in all specimens. Unlike other garnets, where green hues may arise from chromium impurities, uvarovite’s green is inherent to its composition.

Instead of forming large crystals, uvarovite typically grows in clusters of tiny crystals. These clusters, called druzy, create sparkling surfaces that look like green sugar coating the rock beneath.

Under ultraviolet light, it shows an unexpected red glow, adding another layer of interest for collectors. This fluorescence is a unique feature not commonly found in other garnets.

These stones rarely grow large enough for traditional gem cutting. However, their natural crystal formations are so beautiful that they’re often left in their original state. The tiny crystals catch light from multiple angles, creating a dazzling display.

Rhodolite Garnet

Rhodolite garnet stands out with its beautiful purple-red to raspberry-pink colors. The colors can shift between purple and red depending on the lighting, creating an interesting play of hues. This color range makes it distinctly different from the deeper reds of other garnets.

The stone’s clarity is typically excellent, with very few internal features visible to the naked eye. The surface has a glass-like shine that enhances its natural beauty.

What makes rhodolite special is its mixed composition of two different garnet types. This mixture creates its unique color range and optical properties. The stone often shows stronger color saturation in its center, fading slightly toward the edges.

Rhodolite garnet is particularly valued for its vibrant colors that can mimic more expensive gemstones like rubies and amethysts, making it a popular choice among collectors and jewelers alike.

Hessonite Garnet

Hessonite garnet showcases warm honey-to-cinnamon colors, ranging from golden yellow to deep reddish-brown. Some pieces display hints of purple, creating complex and appealing color combinations.

Inside the stone, you might find interesting patterns created by tiny needle-like crystals. Unlike many gems where inclusions reduce the value, these internal features are appreciated in Hessonite. They create unique patterns that make each stone one-of-a-kind.

The stone’s transparency varies from crystal clear to slightly cloudy. This variation can create interesting effects, especially when light passes through the stone. Some pieces show a subtle glow that seems to come from within.

High-quality hessonite stones are relatively uncommon, especially in larger sizes. Their warm colors and unique internal features make them particularly interesting to collectors.

Tsavorite Garnet

Tsavorite garnet displays a brilliant green color that ranges from bright lime to deep forest green. This stunning color comes from tiny amounts of chromium and vanadium in the stone.

The green is so pure and vibrant that it often matches or surpasses the color of fine emeralds. The surface has a glass-like shine that makes the stone look alive with movement.

Each tsavorite has its own personality in terms of color depth and brightness. Some stones show subtle color changes under different lighting, while others maintain a consistent deep green.

Star Garnet

Star garnet shows a fascinating light pattern that looks like a star floating on its surface. This effect, called asterism, comes from tiny needle-like crystals inside the stone. The star usually has four or six rays that move as you turn the stone under light.

The stone’s color is typically deep red to purple-red, often with brown undertones. When polished into a smooth, rounded shape, the star effect becomes more prominent.

The best specimens show sharp, well-defined star rays against a rich, even background color. These stones are quite special because not all garnets can form stars.

The right conditions during formation must exist for the star effect to develop. The tiny crystals inside must align perfectly to create the star pattern. The star effect is natural and permanent – it won’t fade or change over time.

What Rough Garnets Look Like?

Garnets display unique identifying traits when found in their raw, natural state. Look for these distinguishing features:

Look for Distinctive Angular Shapes

Raw garnet typically forms in dodecahedral or trapezoidal crystal shapes. Think of it like tiny, naturally-formed geometric shapes.

Unlike smooth river rocks, rough garnets have sharp edges and flat faces. Even when broken, they tend to maintain these angular patterns. You’ll often spot them as chunky, block-like crystals that look like they’ve been roughly carved.

Check the Color Range and Transparency

Garnets aren’t just red! Look for deep wine colors, but also keep an eye out for orange-brown, green, or even black varieties.

Hold it up to light – rough garnets often show some translucency at the edges, even if the center seems opaque.

Examine the Surface Texture

Raw garnets have this unique, almost greasy-looking surface luster. Not shiny like glass, but more like wet plastic.

Run your finger over it – you should feel a smooth yet slightly waxy texture. If it’s been weathered, the surface might be slightly pitted or rough, but you’ll still see that characteristic luster in protected areas.

Test the Hardness and Toughness

Here’s a quick field test: garnets can easily scratch a penny but won’t scratch quartz. They’re surprisingly heavy for their size – noticeably heavier than a similar-sized piece of quartz or feldspar. Don’t be fooled by lighter stones that look similar!

A Quick Request About Collecting

Tips on Where to Look

To increase your chances of finding garnets, focus your search on these favorable areas:

Metamorphic Rock Outcrops

Look for dark-colored metamorphic rocks, especially schist and gneiss. These rocks often have visible layers or bands.

Garnets appear as dark red or brownish-red crystals embedded in the rock. Common near hiking trails and road cuts where metamorphic rocks are exposed.

Stream Beds & Gravel Banks

Check gravel deposits in streams, especially after heavy rains. Garnets are heavier than most minerals, so they concentrate in stream bends where water slows down.

Use a pan or sieve to sort through the gravel, keeping an eye out for the distinctive reddish crystals that glimmer when wet.

Pegmatite Areas

Search around pegmatite formations, which are coarse-grained igneous rocks that sometimes form large crystal pockets where beautiful garnet specimens can be found nestled among other minerals like mica and feldspar.

These areas often have scattered surface rocks and exposed cliff faces that weather over time, releasing garnet crystals.

Old Mining Areas

Explore permitted public mining dumps and tailings piles near historical mica or feldspar mines, where garnet was often discarded as a byproduct during past mining operations and can still be found in abundance among the leftover material.

Some Great Places To Start

Here are some of the better places in the state to start looking for garnet:

Custer Mining District

Custer Mining District is a historic area in South Dakota that began with the Black Hills Gold Rush. This district has more than just gold, though; it’s packed with many minerals.

Today, rockhounds come here searching for garnets, especially the deep red almandine variety. The High Climb Mine, about six miles north of Custer town, is a top spot to look. Here, garnets grow mixed with biotite and muscovite minerals.

Many collectors visit this mine because the garnets come in different sizes and often appear alongside other minerals like sillimanite and tourmaline.

Another good location is two miles south of Custer, where garnets hide in schist rocks. The Beecher Lode in the district also has garnets. In short, this district offers plenty of chances to find these beautiful red crystals in their natural settings.

Hill City Area

Hill City Area in Pennington County sits among the beautiful Black Hills. This area contains very old metamorphic rocks that have been pushed up by granite bodies. The many changes in the Earth here created the perfect conditions for minerals to form.

Garnets show up in the metamorphic schists of the Oreville Formation. These special rocks contain mica minerals like biotite and muscovite, with garnets often lined up along the rock layers.

Finding these red gems means looking in the right places. Spring Creek west of Oreville has some of the best spots to search. Here, you can see layers of mica schist with garnets embedded right in the rock. Rock collectors often check these outcrops carefully to find good garnet samples.

Keystone Area

Keystone Area is a small town with strong mining roots located near Mount Rushmore. While many tourists visit for the famous monument, rock collectors come for the mineral treasures hiding in the surrounding hills.

The area features ancient metamorphic rocks, particularly schists containing quartz, biotite, and garnets. These rocks formed under extreme heat and pressure millions of years ago.

Bob Ingersoll Mine near Keystone is a favorite spot for finding almandine garnets. Many loose, gem-quality red crystals have been discovered here, making it popular with collectors. Peerless Mine, about half a mile south of town, offers another good hunting ground.

Moreover, Highway 16A provides easy access to garnet-hunting spots. Roadcuts about half a mile north of Keystone expose garnet-bearing schists where anyone can examine and collect samples right from the rock face.

Rattlesnake Butte

Rattlesnake Butte is located in Jackson County within the Pine Ridge Indian Reservation. This distinctive hill is famous for its unusual sand calcite formations. These special crystals formed when calcite grew and trapped sand grains inside, creating unique textures.

Garnets can be found embedded within these sand calcite formations as small, well-formed crystals. They appear alongside other heavy minerals like tourmaline, staurolite, and zircon.

Finding garnets here means carefully examining the calcite crystals that have sand inclusions. The presence of garnets within these formations helps scientists understand where the sand came from and how Rattlesnake Butte formed.

The hill contains an interesting mix of other minerals too, including hornblende, augite, magnetite, and volcanic glass pieces. Rock collectors appreciate this location for its unusual combination of garnets within sand calcite, something not commonly found in other collecting areas.

Spearfish Canyon

Spearfish Canyon cuts through the northern Black Hills with its tall limestone cliffs and beautiful waterfalls. This 20-mile canyon was carved by Spearfish Creek over millions of years and now follows along Highway 14A.

Rocks in the canyon walls tell a story that goes back 300 million years, when this area was under ancient seas. Different geological processes created conditions perfect for mineral formation, including garnets.

Bridal Veil Falls area offers good opportunities to spot garnet-bearing rocks after a short hike from the highway. Little Spearfish Creek, especially near Roughlock Falls, has outcrops and gravel beds where garnets sometimes appear.

The Savoy area, including trails to Spearfish Falls, shows exposed metamorphic rocks that may contain garnets. Unlike many South Dakota locations, Spearfish Canyon combines stunning natural beauty with mineral collecting possibilities, making it enjoyable even if your search for garnets isn’t successful.

Places Garnet has been found by County

After discussing our top picks, we wanted to discuss the other places on our list. Below is a list of the additional locations along with a breakdown of each place by county.