At first glance, the Moon appears to be covered in the same gray material everywhere.

It isn't.

Lunar regolith is a complex mixture of minerals, broken rock, impact glass, breccias, agglutinates, and extremely fine particles produced and reworked over billions of years. Its composition changes depending on where you are on the Moon, what rocks lie beneath the surface, and how material has been redistributed by impacts.

That variability is increasingly important.

For most of lunar science history, lunar regolith composition helped researchers understand how the Moon formed and evolved. Today, engineers also need to understand what lunar regolith is made of because the material will become the working surface—and potentially one of the largest sources of raw material—for future lunar operations.

Rovers have to drive through it. Excavators have to dig it. Construction systems may melt or compact it. Resource-processing systems may extract oxygen and metals from it.

The question is no longer simply:

What is Moon dust made of?

It is also:

What does its composition mean for the hardware we plan to operate on the Moon?

What Is Lunar Regolith Made Of?

Lunar regolith is made of rock fragments, individual mineral grains, impact and volcanic glass, breccias, agglutinates, and fine lunar dust.

These materials form the loose, unconsolidated layer covering most of the Moon's bedrock.

The primary mineral components found throughout lunar material include:

• Plagioclase feldspar
• Pyroxene
• Olivine
• Ilmenite
• Spinel and other minor minerals

A review of lunar mineral resources published in Planetary and Space Science identifies plagioclase, pyroxene, olivine, ilmenite, and spinel among the major minerals present in lunar regolith.

But those mineral grains represent only part of the material.

Repeated meteoroid impacts continuously fracture, melt, weld, and mix the lunar surface. As a result, lunar soil also contains:

Rock fragments
Pieces of basalt, anorthosite, breccia, and other lunar rocks.

Monomineralic grains
Individual fragments of minerals such as plagioclase, pyroxene, or olivine liberated when larger rocks break apart.

Impact glass
Glassy material produced when impacts rapidly melt lunar material and it cools again.

Agglutinates
Complex particles created when micrometeorite impacts partially melt and weld smaller grains together.

Breccias
Rocks composed of previously broken fragments that have been consolidated by impact processes.

That means lunar regolith is not simply crushed lunar bedrock.

It is a material that has been processed by the lunar environment for billions of years.

Recent analysis of returned Chang'e-5 and Chang'e-6 material continues to show regolith containing basaltic fragments, impact-melt breccias, agglutinates, monomineralic fragments, and glasses.

What Minerals Are on the Moon?

The major minerals in lunar regolith tell us a great deal about the geological terrain from which the material originated.

Four mineral groups are particularly important for understanding lunar surface composition.

Plagioclase: The Mineral Behind the Lunar Highlands

Plagioclase feldspar is one of the defining minerals of the lunar highlands.

Much of the Moon's ancient crust is composed of anorthositic rock rich in calcium-bearing plagioclase, particularly anorthite.

Remote mineral mapping published in Geophysical Research Letters estimated the average abundance of plagioclase in the lunar highlands at approximately 75%, with some areas approaching essentially pure anorthosite.

Returned lunar samples provide even more dramatic examples. Apollo 15 anorthosite sample 15415 consists almost entirely of anorthite, demonstrating just how plagioclase-rich portions of the lunar crust can be.

Why Plagioclase Matters for Lunar Engineering

For engineers, high plagioclase abundance is more than a geological fact.

It affects:

• bulk chemistry
• aluminum and calcium content
• iron abundance
• optical properties
• melting and processing behavior
• potential ISRU products

Plagioclase-rich terrain is generally associated with the bright lunar highlands, while iron- and titanium-rich mare materials tend to appear darker.

This becomes particularly relevant as missions move toward the lunar south polar region, much of which lies within or near feldspathic highlands terrain.

If your mission is targeting the lunar highlands, testing exclusively with basalt-rich terrestrial material may reproduce the wrong mineralogical environment.

Anorthosite and the Lunar Highlands

The terms plagioclase and anorthosite are closely connected, but they are not interchangeable.

Plagioclase is a mineral.

Anorthosite is a rock composed predominantly of plagioclase.

The Moon's ancient crust is strongly associated with ferroan anorthosite. Research on lunar highlands material describes primary crustal anorthosites containing greater than 90% calcium-rich plagioclase by mode.

This composition is one of the strongest pieces of evidence for the lunar magma ocean model.

As the early Moon cooled from a largely molten state, relatively low-density plagioclase crystals are thought to have floated upward, contributing to the formation of an early anorthositic crust.

Today, those rocks have been pulverized and redistributed into the regolith.

So when we talk about highlands lunar regolith composition, we are often talking about regolith with a strong anorthositic—and therefore plagioclase-rich—heritage.

Pyroxene: A Major Mineral in Lunar Basalts

Pyroxene is one of the dominant mafic minerals found in lunar basaltic material.

It contains varying amounts of magnesium, iron, calcium, silicon, and oxygen and occurs throughout many lunar rocks and soils.

Pyroxene becomes particularly important in the lunar maria, where ancient basaltic lava flows produced the large dark plains visible from Earth.

Chang'e-5 samples from Oceanus Procellarum provide modern ground truth for this type of material. Studies of the returned soil identify pyroxene, plagioclase, and olivine as primary minerals in the Chang'e-5 lunar soil.

Why Pyroxene Matters

Pyroxene affects:

• iron and magnesium availability
• oxygen extraction chemistry
• spectral behavior
• melting characteristics
• glass production
• construction processes

Its composition can also tell scientists about the magma from which the original basalt crystallized.

For an ISRU or construction system, however, the important point is simpler:

Changing the pyroxene content changes the feedstock.

Olivine in Lunar Regolith

Olivine is another magnesium- and iron-bearing silicate found in lunar material.

It commonly occurs alongside pyroxene in basaltic and deeper-derived lunar rocks.

Olivine is particularly interesting because changes in its iron-to-magnesium ratio carry information about the material's geologic origin and evolution.

From an engineering perspective, olivine also represents another mineral phase containing chemically bound oxygen and potentially useful metals.

Its abundance therefore contributes to the overall chemistry and processing behavior of lunar regolith.

Chang'e-5 analyses have confirmed olivine alongside pyroxene and plagioclase in returned mare soil.

Ilmenite: A Small Mineral With Large ISRU Significance

Ilmenite is an iron-titanium oxide with the formula FeTiO₃.

Its concentration varies significantly across the Moon and is typically more important in some mare basalts than in the feldspathic highlands.

Although ilmenite may represent a relatively small fraction of many lunar soils, it has received disproportionate attention in lunar resource research.

Why?

Because it contains:

• iron
• titanium
• oxygen

and can participate in reduction reactions used to liberate oxygen.

Hydrogen reduction of iron-bearing lunar materials, including ilmenite, has been one of the most extensively investigated lunar oxygen-production pathways. Reviews of lunar oxygen extraction technologies describe hydrogen reduction among the more mature concepts explored for lunar ISRU.

That makes ilmenite a useful example of why lunar regolith mineralogy matters more than simply knowing elemental composition.

Two regoliths can both contain oxygen, iron, and titanium while placing those elements in different mineral phases.

How those elements are mineralogically bound can change how easily they can be processed.

Lunar Regolith Contains Glass

One of the biggest differences between lunar regolith and many ordinary terrestrial soils is its abundance of glassy material.

Glass can form through several mechanisms on the Moon.

Impact Glass

High-velocity impacts generate enormous localized temperatures and pressures.

Material can melt almost instantaneously and then cool rapidly, producing glass.

Volcanic Glass

Some lunar volcanic eruptions also produced glassy particles, including well-known orange and green volcanic glasses returned during Apollo missions.

Glass in Agglutinates

Micrometeorite impacts can partially melt the surface of regolith particles and weld several grains together into complex glass-rich structures called agglutinates.

Agglutinates are therefore not simply individual minerals.

They can contain mixtures of:

• mineral fragments
• glass
• rock fragments
• extremely fine metallic iron

This is important because glass content can affect how regolith melts, flows, absorbs energy, and responds during processing.

Experiments investigating rapid melting of lunar regolith have shown that different mineral phases behave differently during thermal processing, reinforcing that the original mineralogical composition affects the behavior of the final melted material.

What Are Lunar Agglutinates?

Agglutinates are composite lunar soil particles created when micrometeorite impacts partially melt and weld regolith grains together.

They are one of the characteristic products of lunar space weathering.

Unlike anything produced by conventional terrestrial erosion, agglutinates can contain multiple mineral and rock fragments trapped inside impact-generated glass.

Modern three-dimensional studies continue to reveal the highly complex internal structure of these particles. Research on lunar agglutinates describes them as aggregates produced through the adhesion and welding of smaller rocks, mineral fragments, and metallic particles.

Agglutinates matter because their presence changes more than composition.

They can influence:

• particle morphology
• optical properties
• density
• mechanical behavior
• volatile storage
• melting behavior

Again, composition and physical properties are connected.

Lunar Highlands vs. Lunar Mare Composition

The easiest way to understand broad differences in lunar soil composition is to compare the Moon's two most recognizable terrain types.

Modern chemical mapping supports this large-scale distinction.

A 2023 Nature Communications study using returned Chang'e-5 samples to improve global lunar chemistry maps found that mare regions are generally enriched in FeO, TiO₂, and MgO compared with the highlands, while the highlands contain higher Al₂O₃, CaO, and SiO₂ abundances.

That is one reason the Moon does not have one universal lunar regolith composition.

The geology beneath the regolith matters.

Lunar Mare Regolith Composition

The dark regions visible from Earth are the lunar maria, enormous plains created primarily by ancient basaltic volcanism.

Over billions of years, impacts broke those basalt flows apart and incorporated them into the lunar regolith.

Modern sample analysis shows that mare regolith typically contains a combination of:

• basalt fragments
• pyroxene
• plagioclase
• olivine
• ilmenite
• impact-melt breccia
• agglutinates
• glass
• monomineralic fragments

A 2026 study comparing Chang'e-5 and Chang'e-6 materials notes that lunar mare regolith is well established as containing primarily basaltic components together with impact breccias, micrometeorite-generated agglutinates, and individual mineral fragments.

But even mare regolith isn't one material.

Different basalt flows contain different concentrations of titanium, iron, aluminum, magnesium, and other elements.

Chang'e-5 demonstrated this directly. Its returned samples represented a younger basaltic terrain with chemistry distinct from many previously sampled Apollo and Luna mare materials.

Lunar Highlands Regolith Composition

The lunar highlands are older, brighter, and generally much more plagioclase-rich.

Typical highlands regolith includes material derived from:

• anorthosite
• norite
• troctolite
• impact breccias
• mineral fragments
• glass
• agglutinates
• material transported from other locations by impacts

This last point is important.

A highlands location does not necessarily contain only highlands material.

Large impacts can throw material tens, hundreds, or even thousands of kilometers across the Moon.

Regolith is therefore a mixture of local geology and transported material.

That becomes increasingly important when trying to predict the precise mineralogy at a future landing site.

What Is Lunar South Pole Regolith Made Of?

The lunar south polar region is particularly important because many future exploration and resource missions are targeting it.

But “lunar South Pole regolith” should not be treated as a single standardized material either.

Much of the region is associated with ancient feldspathic highlands, but impact processes—especially those associated with the enormous South Pole–Aitken Basin—have exposed, excavated, transported, and mixed material from different depths and geological units.

Modern global chemistry mapping identifies the South Pole–Aitken Basin as chemically distinguishable from both typical mare and highlands terrain. Its concentrations of FeO, TiO₂, Al₂O₃, CaO, MgO, and SiO₂ form a distinct compositional signature.

Chang'e-6 has now added something even more valuable: actual farside samples from the South Pole–Aitken region.

Analysis of the Chang'e-6 landing area and returned material shows a mixture including local mare basalt, breccias, agglutinates, glasses, and non-mare material transported or excavated by impacts.

The implication for engineering is important:

“South Pole simulant” cannot be defined simply by latitude.

Mission geology matters.

The Chemical Composition of Lunar Regolith

Mineralogy tells us which minerals are present.

Chemistry tells us which elements and oxides make up those minerals.

Across the lunar surface, major chemical components commonly include:

• SiO₂
• Al₂O₃
• FeO
• MgO
• CaO
• TiO₂

Their proportions vary substantially with terrain.

Globally, modern mapping based on sample-return calibration shows that SiO₂ is a major component across essentially all lunar terrains, while iron, titanium, aluminum, magnesium, and calcium vary in ways that help distinguish mare, highlands, and South Pole–Aitken materials.

But it is important not to confuse chemical composition with mineralogical composition.

Knowing that a material contains:

Fe + Ti + O

does not tell you whether those elements are present as ilmenite, pyroxene, glass, or another phase.

For engineering and ISRU, that distinction can be critical.

Lunar Regolith Is Mostly Oxygen—But Not Breathable Oxygen

One of the more surprising answers to “What is Moon dust made of?” is oxygen.

Not oxygen gas.

Chemically bound oxygen.

Oxygen is incorporated into silicate and oxide minerals throughout lunar regolith. Engineering analyses commonly estimate that lunar regolith contains more than 40% oxygen by mass, depending on composition.

That oxygen is locked inside materials such as:

• plagioclase
• pyroxene
• olivine
• ilmenite
• glass

Extracting it requires energy and chemical or electrochemical processing.

If successful, lunar oxygen could potentially support:

• life-support systems
• oxidizer production
• metals production
• industrial processing

This is one reason regolith has shifted from being viewed simply as the ground on the Moon to being considered a potential ore body.

Why Lunar Regolith Composition Matters for ISRU

There is no single optimal process for extracting resources from every lunar soil.

The mineralogy of the feedstock affects what can be extracted and how efficiently a process can extract it.

Potential lunar ISRU pathways include:

• hydrogen reduction
• molten regolith electrolysis
• molten-salt electrolysis
• carbothermal reduction
• thermal processing
• mineral beneficiation

Reviews of lunar ISRU technologies emphasize oxygen extraction as one of the central resource-utilization opportunities because oxygen-bearing minerals are distributed throughout the lunar surface.

The choice of process can depend on which minerals are present.

For example, a hydrogen-reduction system can respond differently to iron-rich mare material than to strongly plagioclase-rich highlands regolith.

That creates a direct engineering chain:

location → geology → mineralogy → chemistry → process performance

A system developed against the wrong composition may still function.

But it may not function the same way at its intended landing site.

Why Lunar Regolith Composition Matters for Construction

The same issue applies to lunar construction.

Regolith is being investigated as potential feedstock for:

• sintered landing pads
• roads
• bricks
• pavers
• structural elements
• radiation shielding
• glass
• ceramics
• additive manufacturing

But regolith does not melt or sinter independently of its composition.

Different minerals:

• absorb energy differently
• soften at different temperatures
• melt at different temperatures
• form different crystalline phases while cooling
• produce different mechanical properties in the finished material

Laboratory studies of lunar regolith simulants have demonstrated that mineralogical composition plays an important role in sintering and consolidation behavior.

Research into melting individual lunar-regolith particles similarly shows distinct behavior among mineral phases such as pyroxene and ilmenite.

So when someone says:

“We're going to 3D print with Moon dirt,”

one of the first engineering questions should be:

Which Moon dirt?

Composition Affects More Than Chemistry

This is where lunar regolith mineralogy becomes especially interesting.

Composition can influence properties that initially appear unrelated to chemistry.

Different minerals and glass fractions can affect:

• reflectance and albedo
• thermal behavior
• dielectric properties
• particle density
• hardness
• abrasion
• melting behavior
• magnetic response
• mechanical behavior

The Moon's familiar visual contrast provides the simplest example.

Plagioclase-rich highlands are generally brighter, while iron- and titanium-bearing basaltic mare surfaces are darker.

Global mineral mapping has shown strong spatial relationships between plagioclase and mafic mineral abundance across the Moon.

That matters when designing sensors, thermal systems, optical systems, or equipment whose behavior depends on interaction with the surface.

Lunar Regolith Composition Changes From Place to Place

Perhaps the most important lesson is that there is no universal recipe for lunar regolith.

Composition varies because of:

Underlying geology

A basalt flow produces different regolith than an anorthositic highland crust.

Impact mixing

Impacts excavate deeper rocks and redistribute material across large areas.

Space weathering

Micrometeorite bombardment and solar-wind exposure continually alter grains and generate glass-rich agglutinates.

Volcanic history

Different lava flows contain different mineral and chemical compositions.

Depth

Surface regolith can contain different proportions of mature space-weathered material than material buried below it.

Geographic location

Apollo, Luna, Chang'e-5, and Chang'e-6 samples demonstrate that different regions of the Moon can possess substantially different compositions.

Recent sample-return missions are therefore doing more than adding rocks to our lunar collection.

They are demonstrating how dangerous it can be to think of “the Moon” as one material specification.

Why Lunar Regolith Simulants Need Different Compositions

Actual lunar material is extremely limited.

Almost every lunar technology must therefore be developed using lunar regolith simulants made from terrestrial minerals and rocks.

But a simulant cannot reproduce every lunar property perfectly.

The right composition depends on what is being tested.

ISRU testing may prioritize:

• mineral phases
• bulk chemistry
• iron-bearing minerals
• glass content
• oxygen-bearing phases

Construction testing may prioritize:

• mineralogy
• glass content
• particle size distribution
• melting behavior
• sintering behavior

Rover testing may prioritize:

• particle size distribution
• particle shape
• density
• shear behavior
• cohesion

Optical testing may prioritize:

• mineralogy
• iron content
• albedo
• particle size

Peer-reviewed characterization of lunar highlands and mare simulants has shown why this application-specific approach matters: materials designed for different geological regions can reproduce different mineralogical and chemical characteristics of actual lunar regolith.

There is therefore no scientifically useful answer to:

“What is the most accurate lunar regolith simulant?”

without first asking:

“Accurate for what property, location, and test?”

From Lunar Composition to Lunar Engineering

For scientists, lunar regolith is an archive of the Moon's geological history.

For engineers, it is becoming something else:

feedstock, terrain, construction material, dust source, thermal environment, and operating surface—all at the same time.

Understanding what lunar regolith is made of helps explain how all of those systems will behave.

Plagioclase abundance can change chemistry and optical behavior.

Pyroxene and olivine change iron and magnesium content.

Ilmenite affects titanium abundance and certain oxygen-extraction pathways.

Glass changes thermal processing behavior.

Agglutinates change both composition and particle morphology.

Basaltic mare material behaves differently from plagioclase-rich highlands material.

And the South Pole introduces still more geological complexity.

The future of lunar surface operations will therefore require more than simply learning how to work in “Moon dust.”

It will require designing for the specific lunar material beneath the mission.

Frequently Asked Questions About Lunar Regolith Composition

What is lunar regolith made of?

Lunar regolith is made of rock fragments, mineral grains, glass, breccias, agglutinates, and fine dust. Common minerals include plagioclase, pyroxene, olivine, ilmenite, and minor mineral phases.

What is Moon dust made of?

Moon dust is the extremely fine fraction of lunar regolith. Its exact composition varies by location but can contain fragmented minerals, glass, tiny rock fragments, agglutinate material, and products of space weathering.

What minerals are on the Moon?

Major lunar minerals include plagioclase feldspar, pyroxene, olivine, and ilmenite, along with spinel and numerous minor minerals. Their abundances differ greatly across geological terrains.

What is lunar highlands regolith made of?

Lunar highlands regolith is generally plagioclase-rich and anorthositic, with additional pyroxene, olivine, impact glass, breccias, agglutinates, and material transported from surrounding terrains. Global mineral maps estimate average highlands plagioclase abundance at roughly 75%, although some regions are considerably richer.

What is lunar mare regolith made of?

Lunar mare regolith is derived largely from basaltic lava flows and commonly contains pyroxene, plagioclase, olivine, varying amounts of ilmenite, basalt fragments, glasses, breccias, and agglutinates.

Does lunar regolith contain oxygen?

Yes. Lunar regolith contains large amounts of oxygen chemically bound within silicate and oxide minerals. Engineering analyses commonly place its oxygen content above 40% by mass, although it is not present as breathable molecular oxygen and must be extracted through processing.

Is lunar regolith the same everywhere on the Moon?

No. Lunar regolith composition varies by location, underlying geology, impact history, depth, and space-weathering history. Modern sample-return and global-mapping studies show significant chemical and mineralogical differences among lunar highlands, mare regions, and the South Pole–Aitken Basin.

The Moon Is Not Made of One Kind of Dirt

Calling lunar regolith “Moon dust” makes the surface sound deceptively simple.

It isn't.

The Moon contains different terrains, different rocks, different minerals, different chemical compositions, and billions of years of impact-generated mixing.

Those differences tell scientists where the Moon came from.

Increasingly, they also tell engineers what their machines will have to work with when they get there.

Understanding lunar regolith composition and mineralogy will influence how we design rovers, build infrastructure, extract oxygen and metals, process construction materials, and ultimately establish a sustained human presence on another planetary surface.

Before we can build with the Moon, mine the Moon, or live on the Moon, we have to understand what the Moon is made of.