Hawaii is known for its beautiful beaches and volcanoes, but it’s also a place where you can find a variety of rocks, minerals, and gems. The types of rocks found in Hawaii can be quite diverse, making it an interesting spot for rock enthusiasts.

However, finding these natural wonders can be challenging if you don’t know what to look for or where to start. Without knowing what to look for or where to look, finding these natural wonders can be very challenging.

For example, minerals like peridot, allophane, and obsidian are found in Hawaii, but identifying them requires a bit of skill. Learning about these rocks and where they’re likely to be found can turn a simple hike into an exciting treasure hunt.

A List of The Common Rocks, Stones, and Minerals Found in Hawaii

Hawaii is a paradise not just for its beaches and landscapes, but also for its fascinating variety of rocks and minerals. Find out more about the state’s geology with the help of these guides:

• Hawaii rockhounding
• Hawaii geodes

The Hawaii State Rock, Mineral, and Gem

Here is the state gem chosen to represent Hawaii:

Exploring Hawaii’s natural beauty through rockhounding can be an exciting adventure, but it’s important to know the rules to protect the environment.

The Hawaii Department of Land and Natural Resources (DLNR) offers helpful tips and guidelines for rock collecting to ensure everyone can enjoy this activity responsibly.

Apatite

Apatite is a mineral that comes in many colors, like blue, green, and yellow, making it pretty cool to look at. It gets created in different ways, including in volcanic rocks and as part of bones and teeth in animals.

Apatite has a special feature; it can glow under ultraviolet light, which is super interesting to see. Plus, it’s not as hard as some other minerals, which means it can scratch more easily.

People use apatite for making fertilizer because it has phosphorus, which helps plants grow. It’s also cut and polished for jewelry, adding a splash of color to rings and necklaces.

Where you can find apatite in Hawaii

• Hualālai Volcano
• Oahu Island
• Lahaina

Aragonite

Aragonite is a cool mineral that shows up in different shapes like needles, columns, and even as part of pearls and coral.

It appears in places where groundwater has lots of minerals, or in oceans and seas where sea creatures use it to make their shells.

Aragonite can change into another mineral called calcite over time, which is pretty interesting. It also shines or sparkles under light, which makes it really pretty to look at.

Many people use aragonite in aquariums because it helps keep the water healthy for fish by balancing the pH levels. It’s also ground up for use in making things like paper and plastics stronger.

Where you can find aragonite in Hawaii

• Honolulu
• Waiʻanae Range
• Kauai Island

Basalt

Basalt is a dark-colored rock that comes from cooled lava. It covers more of Earth’s surface than any other rock type, especially on the ocean floor.

Basalt has tiny crystals that can be hard to see without a magnifying glass because it cools down fast when lava hits the water or air. This rock is also strong and heavy, making it feel pretty solid when you hold it.

People use basalt for building things like roads and statues because it’s so tough. It’s also ground up to make a kind of rock wool for insulation, keeping houses warm in the winter and cool in the summer.

Where you can find basalt in Hawaii

• Hilo
• Niihau Island
• Lanai Island
• Molokai Island

Calcite

Calcite is a mineral that comes in many colors, from clear to black, and even red and blue. It’s found in rocks and minerals found in Hawaii, showing up in many different environments, like caves and hot springs. 

Calcite can glow under ultraviolet light, making it look super cool in the dark. It’s also known for being able to split into three equal parts along smooth surfaces, which is a neat trick.

Many things around us, like toothpaste and chewing gum, have calcite in them because it’s a good cleaner and safe to eat in small amounts. It’s also used in the construction industry to make cement and concrete stronger.

Where you can find calcite in Hawaii

• Kula Kai Caverns
• Honolulu
• Koolau Range
• Kauai Island

Hematite

Hematite is a shiny, dark-colored mineral that often looks like metal because of its smooth, reflective surface. It forms when iron and oxygen mix together in water or when minerals in rocks react with oxygen. 

Hematite is cool because it can be attracted to magnets and sometimes even act like a weak magnet itself. This feature makes it fun to play with and easy to spot.

This mineral is important because it’s a major source of iron, which is used to make steel. Steel is then used to build things like cars, bridges, and buildings, making hematite very valuable.

Where you can find hematite in Hawaii

• Hualālai Volcano
• Koolau Range
• Kauai Island
• Maui Island

Magnetite

Magnetite is a black, shiny mineral that sticks to magnets, which is super cool to see. It’s made up of iron and oxygen, and you can find it in many places, including beaches, mountains, and even on Mars.

This mineral is special because it can show us where to find north and south, just like a compass. Long ago, navigators used magnetite to help them sail across the oceans without getting lost.

Today, magnetite is used to make steel, which is a material for building strong structures like skyscrapers and bridges. It’s also used in electronics and as a colorant in concrete, making it a very important mineral.

Where you can find magnetite in Hawaii

• Molokai Island
• Lahaina
• Kaula Island
• Honolulu

Quartz

Quartz is one of the most common minerals found all over the world, famous for its hard and crystal-clear appearance. It forms from cooling magma and can be found in many different colors, like clear, pink, or even black.

Quartz is really hard, making it great for making jewelry that lasts a long time. It also doesn’t get scratched easily, so it keeps its sparkle.

Beyond jewelry, quartz is used in making glass, electronics, and even watches because it can keep time very accurately. It’s also ground up and used in construction materials to make surfaces tough and durable.

Where you can find quartz in Hawaii

• Hualālai Volcano
• Honolulu
• Keolu Hills
• Kauai Island

The Gemstones Found in Hawaii

Hawaii is home to a dazzling array of gemstones that capture the essence of the islands’ natural splendor. Learn about some of the best ones you can discover:

Diopside

Diopside is a green to black mineral that looks really pretty when it’s polished. It’s found in rocks that come from deep under the Earth’s surface or from places where volcanoes have erupted.

Diopside is interesting because it can be clear and green, which makes it popular for jewelry. It’s also known for being pretty tough, which means it doesn’t scratch easily.

Besides jewelry, diopside is used in ceramics and as a collector’s mineral. Some types of diopside even glow under certain lights, which adds to its appeal.

Where you can find diopside in Hawaii

• Koolau Range
• Kauai Island
• Āliamanu Crater

Labradorite

Labradorite is a cool mineral that can look gray, but it surprises you with flashes of blue, green, and gold when you move it around in the light. This effect is called labradorescence, and it makes labradorite really special to look at.

It’s found in some types of volcanic rock, popping up in places where the Earth has been really active. The colors shimmer and shine because of the way light bounces off layers inside the mineral.

Labradorite is often used in jewelry like necklaces and rings because of its beautiful colors. It’s also carved into sculptures and used in home decorations, adding a touch of magic to everyday items.

Where you can find labradorite in Hawaii

• Halemaumau crater
• Lanikai Hills
• Āliamanu Crater

Opal

Opal is a gemstone that can show many colors, ranging from clear through white, gray, red, orange, yellow, green, blue, magenta, rose, pink, slate, olive, brown, and black.

It’s made when water runs down through the earth and mixes with silica, and then it dries out and hardens over millions of years. The play of color in opal is called “fire,” and it looks like the colors are dancing inside the stone.

This happens because of the way silica particles inside the opal diffract light. Opal is used in all kinds of jewelry, like rings, necklaces, and earrings, because its color changing makes it very eye-catching.

It’s also carved into beautiful decorative items that catch the light and add beauty to any space.

Where you can find opal in Hawaii

• Hawaii County
• Keolu Hills

Peridot

Peridot is a bright green gemstone that forms deep inside the Earth’s mantle and is brought to the surface by volcanic activity. It’s one of the few gemstones that comes in a single color, a distinctive signature green.

The intensity and tint of the green, depending on how much iron is contained in the crystal structure, determines the value of peridot. This gem shines even in artificial light, making it popular for jewelry.

Peridot is often used in rings, bracelets, and necklaces, adding a splash of color to any outfit. It’s also believed to bring good luck and peace, which makes it a thoughtful gift.

Where you can find peridot in Hawaii

• Black Sand Beach
• Hilo

Sodalite

Sodalite is a rich blue mineral that’s often speckled with white patches or veins, making it look like a night sky filled with stars. It’s found in rocks that were changed by heat and pressure deep within the Earth.

Sodalite glows orange under ultraviolet light, which is a really cool feature not many minerals have. This makes it not just pretty to look at but also fun to explore with a UV flashlight.

It’s typically used in jewelry, like necklaces and earrings, because its deep blue color is very attractive. It’s also carved into decorative items such as vases and sculptures, adding a touch of natural beauty to homes.

Where you can find sodalite in Hawaii

• Honolulu
• Kauai Island

Spinel

Spinel is a colorful gemstone that comes in many colors, including red, pink, blue, and purple. It forms in metamorphic rocks and is sometimes mistaken for ruby or sapphire because of its vibrant colors.

Spinel has a special feature called double refraction, where light splits into two paths as it passes through the gem, making it sparkle. This makes spinel very shiny and attractive, especially under the sun.

Spinel is not just pretty; it’s also very durable, which means it doesn’t scratch or chip easily. This makes it perfect for everyday jewelry like rings and bracelets.

Among the gemstones found in Hawaii, spinel stands out for its beauty and is often used in local jewelry designs. It’s also valued for its rarity and natural brilliance, making it a favorite among gem collectors.

Where you can find spinel in Hawaii

• Koolau Range
• Āliamanu Crater
• Kaula Island

Zircon

Zircon is a gemstone that comes in a variety of colors, including clear, green, blue, and brown. It forms in igneous rocks, which are rocks created by cooling lava or magma.

Zircon is known for its high brilliance and fire, which means it sparkles a lot under light. This makes it a popular choice for jewelry, like rings and necklaces.

However, this mineral is used not just in jewelry but also in the making of ceramics because it can withstand very high temperatures.

Where you can find zircon in Hawaii

• Hamakua
• Hualālai Volcano
• Mauna Kea summit

The Crystals Found in Hawaii

Hawaii’s volcanic landscape is a hidden workshop where nature crafts crystals of incredible beauty. Learn more about what the islands have to offer with our guides:

• Crystal mining in Hawaii

Aegirine

Aegirine is a dark mineral that often appears in long, skinny crystals. It’s usually found in rocks that have changed a lot because of high pressure and temperature deep inside the Earth.

Aegirine stands out because it can be very dark green or almost black, making it easy to spot in rocks. It’s shiny and can look really cool when the light hits it just right.

This mineral isn’t just pretty; it’s also used in research to understand more about how rocks form and change over time. Scientists study aegirine to learn about the conditions deep within the Earth where it grows.

Where you can find aegirine in Hawaii

• Kauai Island
• Lahaina
• Puu Koae

Allophane

Allophane is a type of clay mineral that’s usually found in soils and rocks that have been altered by weather or hot water. It forms when volcanic ash breaks down and mixes with water, creating a soft, earthy material.

This mineral is known for its bright colors, ranging from blue and green to yellow and white. It’s not just colorful; allophane has a cool, smooth texture that’s easy to recognize.

Allophane is used to help clean up the environment because it can absorb different kinds of waste from water. It’s also added to soil to help plants grow better by holding onto nutrients and water.

Where you can find allophane in Hawaii

• Honolulu
• Kauai Island
• Maui Island

Alunite

Alunite is a mineral that forms in areas where sulfuric acid reacts with rocks containing potassium and aluminum. It often appears in bright colors, like yellow, pink, or white, making it easy to spot.

This mineral is interesting because it can tell scientists a lot about the history of the Earth’s surface where it’s found. It shows them where acid has been in action, changing the rocks and soil.

Alunite is used to make alum, which is a chemical important in making paper and purifying water. It’s also used in cosmetics, like deodorant, because it can help stop sweat.

Where you can find alunite in Hawaii

• Mauna Kea summit

Andesine

Andesine is a type of feldspar mineral that can be red, orange, yellow, or even green. It’s often found in volcanic rocks and is part of the crystals found in Hawaii.

This mineral has a cool property of showing different colors when you look at it from different angles. It’s because of the way light scatters inside it, which is something called labradorescence.

Andesine is not just pretty; it’s also used in jewelry, making beautiful and colorful pieces. Besides jewelry, it’s sometimes used in ceramics and glass-making because of how it can handle heat.

Where you can find andesine in Hawaii

• Hualālai Volcano
• Mauna Kea summit

Bauxite

Bauxite is a reddish-brown rock that’s the main source of aluminum, one of the most used metals in the world. It’s made from the weathering of rocks containing aluminum minerals over millions of years.

This rock is usually found near the Earth’s surface in areas with a lot of rain and warm temperatures, which helps it form. Bauxite is interesting because it contains a mix of minerals, not just one single type.

The aluminum from bauxite is used to make all sorts of things, from soda cans to airplane parts. It’s also important in making things like windows and foil for cooking.

Where you can find bauxite in Hawaii

• Kauai Island
• Maui Island

Biotite

Biotite is a black or dark brown mineral that is part of the mica family, which means it can be split into very thin sheets. It forms in both igneous and metamorphic rocks through various geological processes.

This mineral is cool because it has a shiny surface and is flexible when split into those thin layers. Biotite can resist heat well, which is why it’s interesting to scientists and geologists.

Though not used as much in everyday products as other minerals, biotite is important in understanding the Earth’s geology. Researchers study it to learn about the conditions under which rocks form.

Where you can find biotite in Hawaii

• Hualālai Volcano
• Oahu Island
• Kaula Island

Obsidian

Obsidian is a shiny, black volcanic glass that forms when lava cools quickly without forming crystals. It’s usually found near the edges of volcanic lava flows.

This rock is known for its smooth, glass-like surface and sharp edges, which can be sharper than a razor blade. That’s why it was used by ancient people to make tools, weapons, and sharp objects for cutting.

Today, obsidian is still used for making decorative items and jewelry because of its beautiful, glossy appearance. It’s also used in some surgical scalpel blades because of its incredibly sharp edge.

Where you can find obsidian in Hawaii

• Hualālai Volcano
• Kilauea Volcano

The Most Valuable Rocks and Minerals in Hawaii

In Hawaii, some rocks and minerals are not just beautiful; they’re also valuable in many ways, playing key roles in various industrial processes.

These natural resources contribute to the richness of the islands and support advancements in technology and construction.

Goethite

Goethite is a brownish mineral that contains iron and is found in soil and sediment. It forms through the weathering of other iron-rich minerals, especially in wet environments.

This mineral is known for its ability to change colors when heated, turning from brown to red. Because of this, it has been used since the Paleolithic times to make red pigments for coloring.

Today, goethite is mainly used as an iron ore, known as brown iron ore, which is important for making steel. It’s also still used in pigments, giving ochre colors for art and decoration.

Where you can find goethite in Hawaii

• Kauai Island
• Maui Island

Gypsum

Gypsum is a soft mineral that is white or clear and can be scratched with just a fingernail. It forms from the evaporation of seawater and is often found in thick beds or layers.

Gypsum is interesting because when heated, it can turn into a powder and then be mixed with water to form a paste that hardens. This paste is called plaster of Paris, used for making sculptures and casts.

It’s also used to make drywall for building walls and ceilings in houses. Besides construction, gypsum helps farmers improve their soil, making it easier for plants to grow.

Where you can find gypsum in Hawaii

• Makapuu
• Waimea
• Kau Desert
• Kilauea Volcano

Potassium Feldspar

Potassium feldspar is a common mineral that makes up a large part of the Earth’s crust. It forms in both volcanic and metamorphic rocks, showing up in a variety of colors like pink, white, or gray.

This mineral is one of the valuable rocks in Hawaii, where it’s not just pretty to look at but also important for the soil. It has a unique property of cleaving, or breaking, into flat sheets, which is cool to see.

Potassium feldspar is used in making glass and ceramics, which are things like windows and dishes. It’s also an important ingredient in concrete and aggregates, helping to build strong and durable structures.

Where you can find potassium feldspar in Hawaii

• Hualālai Volcano

Pyrite

Pyrite, also known as fool’s gold, is a shiny, metallic mineral that looks a lot like real gold. It forms in many different geological environments and is often found in rocks alongside gold and other metals.

Pyrite is famous for its bright, golden hue and cubic crystals that can catch anyone’s eye. Pyrite can create sparks when it’s struck against metal or another hard material, which is a pretty cool feature.

Although it’s not used as a source of gold, pyrite is valuable in making sulfuric acid. It’s also used in jewelry and decorations for those who love its glittery appearance.

Where you can find pyrite in Hawaii

• Koolau Range

How to Identify The Rocks and Minerals Found in Hawaii

Learning to identify the gems, crystals, and rocks in Hawaii can lead to an exciting treasure hunt. Knowing what to look for and how to recognize these natural beauties can reveal the hidden stories of the islands’ geological past.

Luster

Luster is how a rock, mineral, or gem reflects light, and it’s a great clue to figure out what you’re looking at. For example, quartz shines with a glassy luster that makes it look like a piece of broken glass.

Some minerals have a metallic sheen, like pyrite, which looks shiny and metal-like. This metallic glow is very different from the sparkle of quartz.

By looking at luster, you can tell a lot about a rock or mineral. It helps you see the difference between two minerals that might look alike but have different surfaces.

Streak

The streak test helps you find out the true color of a mineral, which is a big clue to its identity.

By rubbing the mineral across a piece of unglazed porcelain, you can see the color of its powder, which is usually more consistent than the color of the mineral itself.

Hematite, for instance, may look shiny and metallic, but it leaves a red to reddish-brown streak when tested. This is a stark contrast to magnetite, which, despite also being dark in color, leaves a black streak.

Knowing the streak color can help you tell these minerals apart, even when they look similar at first glance. It’s a handy trick for anyone interested in rocks and minerals, making it easier to figure out what you’ve found.

Reaction to Acid

When you drip a small amount of dilute hydrochloric acid on a mineral and it starts fizzing, that’s a big hint you might have calcite or aragonite. This fizzing action happens because the acid reacts with the mineral, releasing carbon dioxide gas.

In Hawaii rock identification, this acid test is very useful for telling apart carbonate minerals from others that look similar but don’t react. It’s a simple method that doesn’t need any fancy equipment, just a careful eye and a drop of acid.

Remember, safety is important, so always wear gloves and goggles when using acid. This test helps make identifying rocks and minerals easier and more fun, giving you quick answers about what you’ve found.

Magnetism

Magnetism is a key feature that can help identify certain rocks and minerals, like magnetite. If a mineral pulls a metal object toward it, like a paper clip or a needle, it shows that the mineral has magnetic properties.

This simple test is a great way to find out if you’ve discovered magnetite, which is known for being naturally magnetic. Just by using a small magnet, you can explore and see which rocks or minerals stick to it.

Remember, not all shiny, metallic-looking rocks are magnetic, so this test helps narrow down the possibilities. It’s a fun and easy way to learn more about the rocks and minerals around you, making it a favorite among rock collectors.

Cleavage and Fracture

Cleavage and fracture are important clues that help identify how minerals break apart. Cleavage means a mineral splits along specific lines, creating smooth, flat surfaces, like how biotite can split into thin sheets.

On the other hand, fracture is how a mineral breaks without any clear pattern. Obsidian, for example, breaks in a pattern called conchoidal fracture, which looks like a curved surface.

These characteristics give us hints about the structure of the mineral and can help distinguish one mineral from another.

Looking at how a rock or mineral breaks can be a fun way to learn more about it and understand its properties better.