Pumice vs. Perlite: What’s the Difference?
Pumice and perlite are organic materials with lightweight qualities that are used in commercial applications for health and beauty products, gardening, home improvement materials, and other industries.
They share similar origins but have different properties that make each unique and more different than alike.
| Property | Pumice | Perlite |
|---|---|---|
| Origin | Formed through volcanic activity | Formed through volcanic activity |
| Composition | Porous rock filled with air | Hydrated obsidian that expands when heated |
| Color | Varies from red to pale gray | Sterile and lightweight white |
| Unique Properties | Contains nutrients for plants | Fire-retardant, sterile, and ultra-absorbent |
| Uses | Soil enhancement, building | Soil enhancement, building, health & beauty |
| Horticulture/Gardening Uses | Helps with drainage and prevents root rot | Creates pockets for aeration and prevents compaction |
| Building Uses | Lightweight filler and insulator | Filler in gas and air tanks, insulation, and coatings |
| Health & Beauty Uses | Exfoliating scrubs for skin | Additive to soaps, cosmetics, and toothpaste |
| Other Industry Uses | Abrasive, cleaning, and landscaping | Filtration aid in various industries, including food and beverage |
| Cost | More expensive | More affordable |
| Availability | Harder to find | Widely available |
This short, yet comprehensive guide will help you fully understand the benefits of each and the most useful applications
What is pumice?
Pumice is a type of rock that forms through volcanic superheating and cooling of rocks.
The result is varying sizes of pieces from pebbles to large rocks. Pumice is formed from small gas bubbles that get trapped inside volcanic lava before it cools.
The process gives pumice its lightweight characteristics and rough texture. It’s a porous rock that comes in varying colors from red, and yellow to pale gray or dusty white, depending on where it’s mined.
Smaller pieces can float on water because of the air trapped inside. Pumice is never processed mechanically for commercial use. It’s mined from the earth and sorted by size and sold in varying sizes and textures.
Unique properties of pumice
Pumice contains nutrients that help to feed certain plants. The chemical analysis reveals calcium, silicon, aluminum, ferric and ferrous oxide, sodium, potassium, calcium, titanium, and magnesium.
It contains igneous rock and silicon elements that give it an abrasive quality.
When pumice is wet, it can float on water, but it becomes heavy as the porous surface absorbs moisture.
In that sense, it is transformative, but the inner chambers that are sealed retain the air trapped from its original formation.
Uses for Pumice
Pumice is useful for a variety of applications. It’s a soil enhancement, an abrasive, and a filler.
Its home and commercial uses are varied but can be summarized within four categories.
Pumice as a soil enhancement
Pumice is a soil enhancement that is used in cactus and succulent mixtures, and some other plants that require adequate drainage.
Small pumice pebbles mixed into potting or regular soil help to create spaces that prevent soil compaction, allowing water to drain away from the roots.
The rock and air pockets create a healthy growing medium that is best for plants that are subject to root rot.
Pumice in building materials
Pumice is added to concrete and some types of cinder blocks for construction industry applications.
The properties make the materials more lightweight. Pumice also has insulative qualities because of its porous qualities and its air-filled spaces.
Pumice in health and beauty products
Pumice stones are used as exfoliants in the beauty industry. Larger pumice stones are used to exfoliate dead skin on the feet.
Some manufacturers grind pumice to a fine consistency and add it to exfoliating scrubs to loosen dead skin in beauty regimens for the face and hands.
Pumice in other industries
Pumice is also used as an abrasive ingredient. It’s commonly used as an additive in commercial polishes, cleaning products for the home, and pencil erasers.
It’s also used in the machinery to create stone-washed jeans in manufacturing plants.
It is also used as an absorbent material to soak up spills of greasy and oily substances on industrial floors and as decorative landscaping material.
What is perlite?
Perlite is formed on the earth through volcanic activity. The amorphous glass melts in lava in a process that hydrates obsidian, trapping the water inside of the rock.
Perlite deposits are mined and processed through an intense heating method.
The temperature is brought to 1600 degrees Fahrenheit, causing the water-filled granules to pop, similar to popcorn.
The material expands to several times its original size, resulting in a sterile and lightweight white material, resembling a manmade product more than an organic rock.
Unique properties of perlite
Processed perlite is a lightweight material that is sterile after processing. It is exceptionally porous and can absorb water, but it usually floats on the top.
It’s light enough to fly away in a stiff breeze. It is non-combustible and resistant to moisture and resistant to rot.
Perlite contains no minerals, nutrients, or buffering materials. It has a flat, platelet-like appearance.
Uses for perlite
Perlite is used commercially for soil enhancement in horticulture, building materials, health and beauty products, and other industries.
Similar to pumice, its uses are primarily within four segments of the commercial/industrial sector.
Perlite as a soil enhancement
Perlite is routinely mixed with potting soil to help as a space filler to aerate compost piles and to create spaces in the soil to prevent compaction and aerate the soil.
It promotes excellent drainage in cactus and succulents.
It also encourages seedling health by creating an airy compost. Perlite also helps to retain some water but promotes drainage near the roots.
Perlite in building materials
Perlite has insulative qualities and is utilized as a filler in spaces for liquid natural gas storage tanks, in hollow masonry blocks, and as a sound dampener for acoustic wall panels.
Since the material has fireproof qualities, it is also used as a type of blow-in insulation because it is non-combustible. Nor does it settle, warp, or shrink.
Perlite is a popular additive in concrete for base pads and roofing materials.
It is also a filler in spray-on applications for heat resistance to 2,000 degrees Fahrenheit. Perlite is an additive in fire-retardant applications.
Perlite is beneficial as a lightweight reinforcer and filler in many other construction-related products.
You will find it in explosives, cultured marble, joint compounds, adhesives, and sealants, the coating for aluminum roofs, epoxies, composite aircraft repair, and ceiling tiles.
It is also an additive to plaster aggregate, coatings, and paints.
Perlite in the health and beauty industry
Perlite’s high purity as a naturally derived mineral makes it an exceptionally beneficial additive in health and beauty products.
It has a high absorption capacity with a gentle abrasive suitable for various personal care and cosmetic uses.
Perlite is in makeup products that feature matte finishes and oil absorption properties for the skin. It is also helpful in exfoliating scrubs and treatments for the skin on the feet, face, and elbows.
You will also find perlite as an additive in some soaps and toothpaste.
Perlite in other industries
Perlite is a versatile material that appears in multiple industries. It’s added to auto body putty, used to stuff toys, and as mild abrasives in commercial and household cleaning products.
Perlite has a high absorption quality, which makes it an ideal substance commonly used in fine grade form to solidify sludges.
It absorbs liquids from various types of liquid spills, without adding to the weight for later cleanup. It’s an affordable solution for cleanups of massive industrial spills.
Perlite helps with environmental restoration projects and residential cleanups.
Perlite is a benefit in the beverage industry as a filter aid. It’s lightweight and sterile and does not impart flavor or odor to the beverages that pass through fine perlite.
It enhances the clarity of liquids and is produced as a filtration aid in various grades.
Perlite also serves as a filtration aid in biochemical, industrial process chemicals, energy, metal workings, air and gas, and other industrial applications too numerous to list here.
What’s the difference between pumice and perlite?
Pumice and Perlite originate as organic materials from volcanic activity on the earth. Both are porous, lightweight, and have multiple commercial uses.
They share commercial and home applications, but this is where the similarities end. Pumice has a different chemical makeup than perlite. It is filled with tiny air vesicles, while perlite fills with water.
Pumice is mined from the ground and sorted according to size. Perlite is mined from the ground, then heated to high temperatures to expel the water and expand the material to many times its size.
Perlite is lighter, floats on the water quicker, and can blow away in the wind. It has some attributes that pumice does not.
Perlite is fire-retardant. It is also sterile and ultra-absorbent. It is in more commercial applications than pumice.
The shape of the particles is different, and it is partially man-made. Also, perlite has no nutritional value for plants. The final distinction is that pumice is more expensive and in shorter supply.
Pumice vs perlite as soil enhancements
Pumice and perlite are soil enhancements that are both used liberally in the horticulture industry. Each contributes to the health of select plants in gardening and potted plant environments.
Some plants can grow in pumice or perlite alone, but they’re used as an additive to soil with varying mixtures depending on the plant type and its nutritional needs.
Pumice and perlite are not the same. Each has different origins and properties, with varied contributions to plant health. Perlite helps create pockets that aerate the soil and prevent compaction.
It is water and vermin-resistant and is long-lasting. It’s best as a compost additive for aeration but can also promote drainage near the roots of cacti, succulents, and other plants prone to root rot.
Pumice is heavier than perlite, and not prone to blowing or floating away in wind and water. It’s beneficial in potted plants to help add weight to the pot for stability.
It promotes drainage for the same plants without as much water absorption. It also serves as a soil filler for aeration and prevents compaction.
The benefit of pumice in horticulture is that it adds healthy nutrients to the soil to feed the plants as it performs other functions.
Perlite has no nutritional value, making pumice the healthiest, although more expensive for horticulture/gardening projects.
Pumice vs. perlite in building materials
In building materials, pumice is for creating a filler that is lightweight and insulative.
It’s in blocks, masonry, and slabs. Pumice adds unique texturing to masonry and brick products.
The most outstanding feature of pumice in building materials is its insulative and filler qualities. Perlite is in a wide array of building applications.
It is insulative and works well as a filler, but appears in far more construction materials.
Perlite is heat-resistant up to 2000 degrees Fahrenheit. It’s used in multiple forms as a filler between gas and air tanks, in spray applications to retard flames, as a heat-resistant insulative material, and as blow-in insulation in buildings.
Perlite is also an additive to paints, epoxies, and various coatings because it is non-combustible.
Pumice vs. perlite in health and beauty products
Pumice is an abrasive for various skin exfoliants. The larger stones are shaped into pumice stones to smooth skin and remove calluses, and finely ground pumice is in liquid exfoliants and scrubs.
Perlite is in more health and beauty products.
Manufacturers add it to various soaps, skin scrubs, cosmetics that absorb skin oils for a matte finish, and toothpaste for a mild abrasive function.
Pumice vs. perlite in other industries
Both pumice and perlite work in cleaning products that use a mild abrasive.
They’re also added to consumer goods such as pencil erasers and used for industrial cleanups for absorption. Perlite has far more applications than pumice.
It also helps filter foods and beverages. It’s a staple for the biochemical, chemical, metalworking, air, and gas industries for filtration purposes.
Final thoughts
Pumice and perlite have similarities, but more differences set them apart.
Pumice is more expensive and harder to find, but perlite offers an affordable alternative with a broader range of applications.
When you’re familiar with the differences, it can help you to choose the superior product for the job.
Pumice and perlite are most commonly used for horticultural purposes to condition soil, but there are hundreds of different uses for each.
Understanding the differences can help you to choose the best product for your projects.