Fire Pit Lava Rocks: What Are They And Which Type Is Best?

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Families across the country are using one standout method to beautify their fire pits, protect them from damage, and improve their function: Lava Rocks. 

Lava rocks commonly come included when you purchase a propane gas fire pit, but not always. Plus they have many other uses in landscaping, gardening, and grilling.

There are myriad fire pit rocks products out there, and it is hard to go wrong when choosing one. However, to help you narrow down your choice if you are considering using them, here are the most popular lava rocks for fire pits.

Best Fire Pit Rocks

Red 3/4 Inch Lava Rock

  • Best seller: also comes in other sizes and colors
  • For use in natural gas and propane fireplaces and fire pits
  • No color additives or chemicals
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Medium Lava Rocks

  • 1/2 Inch to 1 Inch Thick x 10 Pounds
  • Natural, black volcanic lava rocks
  • Sourced and made in the USA
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Midwest Hearth Lava Stones

  • Rounded lava stones in 4 sizes
  • Tumbling removes any sharp edges and gives a uniform shape
  • 10 lbs in each bag
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This section will take you through seven products, one of which is an alternative to Lava Rocks, that you may consider for your firepit.

1. Fire Pit Essentials Lava Rocks

lava rock

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Fire Pit Essentials is a trusted brand that has been around since 2014.

They produce several products to improve the function of your fire pit while making it more aesthetically pleasing. Thus, it is no surprise they manufacture their line of heat-resistant rocks for a fire pit.

Customers almost universally attest to the excellent function of Fire Pit Essentials fire pit rocks. 

Users report they retain heat to keep flames going while protecting the bottom of your fire pit and assisting with drainage. Ordering them gets you 10 pounds of rocks in the size of your choice.

Size options include:

  • 3-5 inches
  • 1-3 inches
  • 3/4 of an inch
  • 3/8 of an inch

Just be aware that though reviews for these indicate they are generally good propane fire pit rocks or gas fire pit rocks, you will have to take some steps to prepare them. 

Some reviews indicate that they will produce an unpleasant smoke if not rinsed, which you can avoid by rinsing them and letting them thoroughly dry. 

A few customers indicate that quality diminished in larger orders of these rocks and that the fire pit rocks were even of such low quality that they exploded when heated. Though it is a slim possibility, its chances are above zero, so prepare your yard and cover your fire pit when it is not in use. 

But we also have an explanation for how this may have happened, which you will see if you keep reading.


2. American Fire Glass Fire Pit Lava Rocks

fire pit rocks
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American Fire Glass’s black lava rocks for fire pits are a simple product with a 76% 5-star rating among customers.

These 1/2-1 inch sized rocks are a fitting top layer over finer rocks in a propane or gas fire pit. 

They will retain the heat needed for sustaining the flame. With distance from the bottom of the fire pit, there will be no risk of overheating. 

American Fire Glass also sells them at a reasonable price and quantity, so you can use the ten pounds of rocks you get with the order for other purposes around the home.

Some customers report chiseling them to make them fit for other purposes too, which is easier to do with the medium rocks they produce.

Smaller amounts could be used with small portable propane fire pits.


 3. Venetian Princess Fire Pit Lava Rocks

heat resistant stones for fire pit
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Venetian Princess’s fire pit lava rocks have one complaint that seems to follow them: they are smaller than advertised.

Despite their smaller size, they still fulfill their function well, but another small group of customers reported experiencing explosions and pops again. 

Such an experience is likely due to using wet lava rocks, and you can avoid it by assuring your rocks for the outdoor fire pit are dry. 

Other than this complaint, Venetian Princess rocks fill a fire pit well and come in two styles: red or black. 

You can get them in either 10 or 40-lb sizes – just be aware they may be smaller than advertised. 


4. Midwest Hearth Lava Stones For Fire Pit

rock for gas fire pit
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Midwest Hearth’s black lava stones have a lovely rounded appearance, giving them an aesthetic edge over other types of fire pit rocks.

But for fulfilling the same function, and sold in the same 10-lb sets, they are more expensive, up to double the cost of previously mentioned lava rocks. 

Though reviews about their ability to keep a fire going are raving, about 20 percent of customers mention that the rocks are not as big as advertised. Many bags are often of smaller rocks and fail to fill a fire pit. 

While these lava stones for a fire pit might be a great top layer above lava gravel, given the cost and inconsistent sizing, we might recommend you buy other products to fill your fire pit table or bowl.


4. Stanbroil Lava Rocks

gas fire pit rock
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Stanbroil’s black and red fire pit lava rocks are in the middle of the price range.

Both types are packaged in 10-lb bags and are sized 1-2 inches.

Most reviews state that these are not only great lava rocks for propane fire pits and enhance the capabilities of such fire pits; they also arrive true to the advertised size.

You can use them as many customers have by chiseling them into smaller rocks to fill the bottom, or leave them as they are. 

Either way, these lava rocks will spice up your fire pit for less than Midwest Hearth’s Lava Stones.

Make sure to take the same precautions recommended earlier, however, and rinse and try them.

When they trap water, that typically produces the explosions or ruptures that customers report. When they are dry, they maintain a fire and will very rarely overheat.


6. Prism Hardscapes

cheap fire pit rock

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Prism Hardscapes premium lava rocks for outdoor fire pits create a pleasing contrast with the red flames on account of their exceptionally dark color.

Their appearance comes at a premium, however, as they are only sold in 40-lb bulk sizes at a current price of about 50 dollars. 

While this is admittedly a decent cost for a large quantity of lava pit fire rocks, research tells me this is a newer product. Prism Hardscapes seems to devote the majority of its resources to building fire pits. 

This focus may be why there are not many reviews for their fire pit rocks, though I am sure they fulfill their function without any problems. 

If you do want to buy a product that may be more reasonably sized and priced and comes with customer testing and reviews, you may want to stick with the highly-rated yet inexpensive products mentioned earlier.  


7. Hiland Fire Pit Glass

lava rock for fire pit
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This fire pit media solution may be the most interesting of the group, and it has the most ratings for a single product out of them, topping 12,000. 

With several color choices that range from clear to black, they give a fire pit a beautiful appearance, particularly when choosing blue. Additionally, very rarely do customers report issues with broken or popping glass, though there are reviews that describe these problems. 

The most common complaint is one that is easily resolved. With high temperatures, the flames will sometimes leave a black coating on some of the rocks.

This is normal and does not pose a danger. If you follow rinsing and washing protocols for them, this black coating goes away. 

Among alternatives to lava rocks, fire pit glass is likely your best choice, though it may cost a little more than bulk quantities of lava rocks.


What Is Lava Rock?

american fire glass review

Lava rock is a naturally occurring stone formed from the cooled lava of an erupted volcano.

Known in geology as igneous or volcanic rocks, they form when lava cools quickly in the open air. This cooling process produces their porous surface and the frequent presence of other heat-resistant materials or minerals.

The most common Lava rock and the one used for fire pits is none other than pumice stones. 

Pumice stones, commercially called lava rocks, are among the most versatile naturally occurring rocks for household purposes.

Pumice stones can:

  • Help remove impurities from water
  • Help trap water for your plants
  • Amplify the abilities of your grill

Most importantly for our purposes, they can advance the capability of your fire pit. 

Lava rocks are generally more sustainable materials to use for a propane or gas fire pit because they can be used several times, unlike wood or charcoal. Wood or charcoal will only burn once and then cannot be used again. 

Since they were already formed from extreme temperatures, lava rocks are naturally heat-resistant and will not burn when exposed to the high temperatures of a propane-fueled fire pit.

Lava rocks can also protect the interior surfaces of your pit from damage due to extreme temperatures.

That’s because though they retain heat, they still keep the flame above them away from the interior of the fire pit. Thus, they have become a choice material for many fire-pit owners who seek to use more durable, reliable materials. 

To use them safely, though, you must remember that their pores can trap water in addition to heat.

If they trap moisture and you start a fire, the heat produces steam at a very high temperature. It is the escape process of this steam that can crack lava rocks or cause them to explode. 

Therefore, cover your fire pit when it is not in use to keep water out and assure that your lava rocks are dry before use. 

How To Add Lava Rock To Fire Pits

How you add your lava rocks to your fire pit will depend on how you wish to create your fire and the size of your fire pit, but the process is usually simple.

First, you will rinse your lava rocks in your backyard with your hose.

We have mentioned this several times but now we can get to the explanation; you are washing the dust off of them because any potential dust will cause smoke and get jammed in the pipes of your fire pit. 

Rinse them thoroughly to assure that you also get rid of any smaller pieces that can obstruct the jets or the pipes. 

After taking these precautionary steps, and leaving them to dry in the sun for about six hours, then you can begin arranging them in your fire pit. 

If you plan to burn wood above your lava rocks, you will arrange them so that room remains. This layer should be about 4-5 inches deep and will give the wood ample room to burn and keep your lava rocks heated. 

If you only use lava rocks, you will pursue a different arrangement. At the least, you will want to fill your pit until the rock level covers or reaches the fire ring of your pit. 

If you want to fill it with more rocks, there are also methods of doing this. Distribute the rocks evenly as you pour them to create a safe and even distribution of heat and flame. 

If you buy lava rocks in bulk and want to use all of them to almost “overfill” the pit, there is also an arrangement for you.

But it will be safest, especially if you have a square or rectangle fire pit, to concentrate the majority of lava rocks toward the middle of the fire pit.

This way you can assure the flame’s heat stays concentrated in the middle and that it has no risk of spilling out onto the sides or causing any danger. 

Lava Rock Vs Fire Glass

what is a glass fire

Both of these materials have gained fire-pit owners’ attention because they conduct heat well and they are durable.

With the increasing use of both, a debate has sparked about which is better, and to help you decide which better suits your preferences, we will explain some similarities and differences. 

Lava rocks are naturally occurring pumice stones formed from cooled lava, but fire glass is artificially manufactured. 

Fire glass is a “tempered” or “fire-certified” glass that has been put through an intense heating and rapid re-cooling process. This process gives it its strength and high heat resistance; it has no risk of exploding or shattering when exposed to fires. 

Fire glass, since it comes in more uniform, regulated shapes than lava rocks, can usually distribute the heat of a fire pit more evenly.

Additionally, the reflectivity and “albedo effect” from its surfaces make the heating process more efficient. In other words, heat bounces off the glass and re-enters the fire, keeping the flame going while using less gas. 

Some homeowners enjoy the aesthetic appeal of fire glass and how it adds extra shine or an element of beauty to a fire. Others prefer the more rustic look of lava rocks, though lava rocks may not heat as evenly as fire glass.

Fire glass has one difference that stands out for many of its would-be users: its price.

You may need up to 40 pounds of fire glass to fill your pit, which can cost over $80. 

But if you have no problem with compromise, you can use a bottom layer of lava rocks and a top layer of fire glass.  

Lava Rock FAQs

red fire pit lava rocks

I have answered some of these questions through discussion of these products, but to make sure that customers use fire pit lava rocks safely and get to enjoy their fire pits, I will go through several frequently asked questions. 

How long do lava rocks last?

Lava rocks, when used correctly and washed on a fairly regular basis, can last up to three years.

In most cases, they will last two years, though not due to their faults or chemical qualities. The eventual build-up of soot and dust from other rocks will begin to wear on them.

Once they begin to look crumbly, you can remove them from your fire pit and replace them.  

Do lava rocks hold heat?

Lava rocks can hold heat for a short amount of time after a fire, from about 20 minutes to an hour.

Their porous nature means that heat escapes quickly. Their pores help retain the fire as the fuel feeds it, but those same pores mean they do not hold heat on their own.  

How much lava rock do I need?

The amount of lava rock you need depends on your fire pit and preferences.

At the minimum, you will want the lava rocks to create a layer of up to about four inches. Starting with a 24-inch plate, you will need one 10-pound bag to create a good lava rock layer.

Every six inches up from 24-inches will require another 10-pound bag.  

Are lava rocks toxic?

No, lava rocks are naturally occurring and involve no artificial chemicals in their creation.

To soften their edges, the only process they sometimes go through is tumbling. Tumbling involves rolling them against each other to chip away their sharper parts.

There are no added chemicals in the process, and the only chemical they are used with will be the propane that fuels your fire pit.  

What happens if lava rocks get wet?

Lava rocks pose a danger if they get wet.

Their pores will trap moisture and water if they get wet. If this moisture is not dried out, or they are not removed from the fire pit to dry before they are put back in, they pop, crack, or explode. 

The moisture in the rocks meets the fire and produces scalding steam. The steam boiling and trying to escape changes the lava rock’s constitution and breaks the rocks apart with force. 

Does lava rock attract bugs?

While the spaces in the rocks may provide a darker shelter for spiders and other insects when they are not helping feed the fire, lava rocks will not attract dangerous pests. 

Why are my lava rocks popping in the fire pit?

They likely have some moisture trapped inside them.

As long as none are cracking, the rocks should pose no danger but take extra precautions to dry them next time. 

Why do lava rocks turn black?

Lava rocks turn black due to the build-up of soot and due to propane’s burn.

Propane burns less clean than gas and can produce a black coating on the rocks over time. This is very common and you can scrub or rinse the black layer off. 

Is lava rock flammable?

Lava rock is not flammable due to its heat-resistant igneous composition.

This is what makes them ideal for fire pits and other types of outdoor fireplaces.

Are all lava rocks the same?

Not all lava rocks are the same.

Some have different chemical and geological compositions caused by the volcano that created them but the consumer does not have the resources to find this out specifically. 

Can you wash lava rocks?

Yes. It helps them maintain their function for years.

Make sure to thoroughly dry the rocks after a wash. You can leave them lying in the sun to do this.

How deep should lava rock be in the fire pit?

Lava rock can be at least four to five inches deep or can go all the way up the brim of your fire pit. It is your decision. 

How can you tell if lava rock is real?

Pumice stones float on water because of their unique formation.

If your lava rock cannot float on water, it is not real. 

Is there gold in lava rock?

No, there is no gold in lava rocks. 

What are the other names for lava rock?

Lava rocks are commonly called pumice stones or volcanic rocks by geologists.

More informally, people often refer to them as fire pit rocks, fire rocks, fire pit stones, or heat-resistant rocks.

What do you put under lava rocks?

You can put layers of finer rocks under lava rocks, or if your fire pit is not a gas or propane fire pit, you can put sand under lava rocks. 

How do you maintain lava rocks?

Start by acquiring a waterproof cover for your fire pit. This will keep your lava rocks from getting moist and posing a danger.

Then, remove and wash them with a hose and soap every six months.

Conclusion 

I hope that rundown of different fire pit lava rocks helped you understand how they work and you can avoid the mishaps that resulted in bad reviews.

They are a more sustainable yet inexpensive material that gives your fire pit a great look while enhancing its ability to heat your backyard.

Check out these rustic fire pit ideas for inspiration on how to use them with your device, or check out the U-MAX propapne fire pit as one example of a model that comes with rocks.

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