Conundrums of a Landscaper Series : Blackstar Gravel

I will preface this post with the statement that my wife thinks I am a total nerd. Landscape nerd. 

I was recently at my favorite rock yard, Whittlesey, buying a ton of Blackstar gravel (sometimes called Basalt) for the small commercial planting seen above. When I thought to myself, "where is Blackstar gravel from?"

The Unfortunate Question

I like to pride myself on the fact that I use native plants and source things as local as possible for my landscape business. I almost did not want to ask where it is from because Blackstar gravel is such a great product. The gravel is functionally one the best for paths and patios. Aesthetically, Blackstar offers a stark contrast to the green of grass or plants. In the right setting it can add a modern touch. If I knew the stone was coming from Arizona or some other far off state I would have a guilty conscious every time I sold it. As I thought about it more, all signs pointed to the fact that it must of come from a secluded beach on Hawaii or something. I have been the the farthest stretches of Texas and never seen a rock like this. The price is much higher compared to similar gravels. After these thoughts flooded my brain, I finally got the nerve to ask the rock yard manager.

The Origins of Blackstar Gravel

Uvalde County, Texas. Yes!

The yard manager let me know a bit of the back story, which I found interesting and thought you may too.

The manager said that the stone was actually Dolomite, not Basalt, like the other name it is frequently called (be sure to read to the end.) According to the manager, the stone is quarried close to Del Rio, Texas, but the reason the price is high is because the railroads use the same gravel to support the railroad ballast. The railroads use it because of its great strength and interlocking qualities. The railroads are driving the demand high for this product, not just the new fancy houses on the east side of Austin.

This new discovery about the Texas sourced Blackstar gravel, fascinated me for a few reasons.

1. Can it really be sourced in Texas? (Despite the good new, I still doubted the stone was from Texas.)

2. Why would a stone commonly be called Basalt when it is actually Dolomite?

First thing I did was call a Geologist buddy. When I mentioned that the stone may be Dolomite and not Basalt, it seemed to make sense to him based off his knowledge of Texas mineral deposits. There was one way to know for sure though.... Hydrochloric Acid of course.

He brought his family over the next day. As our children ran around and played, we ducked behind the garage with our rocks and diluted Hydrochloric acid. The idea was if we pour the acid on the Blackstar gravel and it fizzed it was Dolomite, if not, then it was something else. Dolomite is similar to limestone in composition, and both of carbonate minerals, which react to Hydrochloric acid.  

As both of our heads hunched over the stones with our ears close we poured the hydrochloric acid...... Nothing happened, I said, "those stones must have something wrong with them." We grabbed another handful, and poured some more acid on them, but this time we emptied the vile just to be sure. Nothing happened again. We walked back to our beer bottles as he told me, "I am not really the kind of geologist who is good at rock identification." I gave up on my research for the moment and enjoyed my beer.

Well, as any good researcher would do, I finally "googled" it. After some searching in obscure links, I found the clarifying document. As it goes, Blackstar is in fact Basalt. A very hard dark stone that forms from cooled magma. It is found in many places, but in Texas it can be found around the Chisos Mountains, Fort Davis, Guadalupe Peak, and down along the Rio Grande. The manager at the rock yard was misinformed.

Dolomite can also be found in Texas, but did not really match the description. It can be darker brown and grey, but not quite the black/grey of Blackstar. Dolomite is similar to Limestone in hardness and composition. Turns out when we did our Hydrochloric acid test we should have been able to know instantly that is was not Dolomite, which fizzes just like Limestone.

The Bottom Line

Blackstar is Basalt. Basalt is in Texas. Basalt is extremely durable, functional, and aesthetically pleasing in landscaping. See clarifying document below.

Thinking About Adding Trees to Your Landscape? NOW is the Time!


Fall special for all tree installations before December 15.

Most people assume spring is the only time to work on your landscape, but fall is actually much better, especially in our Texas heat.
Trees need time to set down roots in the fall and winter, so they can thrive in the spring, and actually require far less water to establish in fall and winter as opposed to planting in spring and summer.

So, the truth is, fall is THE time to plant trees!



What type of trees are best for my landscape?

We work with many different species of trees at Terra Dura, but by far our favorites and most recommended are large shade trees which require little water. Not only are they beneficial to the ecosystem and aesthetically beautiful, by installing trees like these to the southwest of your home or office, you can save quite a bit on your utility bills.


Tree spotlight: Mexican Sycamore

The Mexican Sycamore is a great choice for the Austin area. With smooth, white-to-beige peeling bark and large maple-like leaves, It looks very similar to the American Sycamore you may be familiar with, only a bit smaller and with slight differences to the leaf structure.

 While they can grow up to 80 feet in the wild, most of the Mexican Sycamores around here will get up to about 50 feet tall and 30 feet wide. They’re deciduous, meaning their leaves will fall off come winter and grow back in the spring.




Although Mexican Sycamore is not technically native to our area, some experts believe that all sycamore trees descended from an ancestral species which is most similar to the Mexican variety. As it exists today, Mexican Sycamore originates from Guatemala up through Mexico.


Benefits of planting Mexican Sycamore include:

  • They’re drought resistant, which means less worry and maintenance for you in the hot summers when water is scarce, plus a lower water bill.
  • It won’t be long until they fill in your landscape; these guys are really fast growers.
  • Unlike American Sycamores, Mexican Sycamores are immune to bacterial leaf scorch, a very common and damaging disease.
  • They are well adapted to most soil types, which means chances are you’ll have to do little to no soil adaptations to get them thriving.
  • Mexican Sycamores are also pretty hardy against many of the primary predators other trees suffer from, including most insects and diseases.
  • Although they originate from a more tropical climate, Mexican Sycamores have shown to do well in even the colder Austin winters, requiring little extra care.


Ready to plant? Save $$$ with our Fall Tree Special!

We want to help you take advantage of the perfect season for trees!
Terra Dura is offering a tree planting special until December 15.


Pick any of these three recommended low-water shade trees for one flat fee of $500 + sales tax for your 30-gallon* (approximately 8- to 20-foot tall) tree plus its installation.

1. Mexican Sycamore

2. Live Oak

3. Mexican White Oak

*other tree options and sizes are available.


Not sure which type of tree is best for you? No problem! Give us a call at 512-560-0148 today and we’ll help you make the best decision.  And if you know you’re ready to go, contact us now to set up your installation time. Your tree will have lots of time to set its roots and get cozy!


Lighten Up: Make Your Backyard Inviting


Summer heat been giving you the blues? We love Texas for all the outdoor fun we have, but sometimes it's just too hot to be outside.

 Now that the evenings are getting cooler, it is easy to start thinking about relaxing in your backyard a little more. Have you ever considered the way professional landscape lights can enhance your outdoor space?




There are many surprising reasons to install professional landscape lighting:

 1. Aesthetics

Great lighting just looks good. Lighting adds a dimension of beauty to your outdoor space by creating glows, casting shadows, and adding a softness to your environment that standard porch lights can’t provide.

 2. Security

It’s an old trick everyone knows—lighting up your space makes it much harder to hide, and greatly reduces the chances you’ll attract questionable characters or critters. Even keeping your space partially lit at night can make a big difference.

3. Safety

Nobody wants to stumble around or hurt themselves trying to navigate a dark porch or yard. Illuminate dark corners with low lighting to easily see where you’re going at night, and to keep your space safe for kids and family.

 4. Extended Outdoor Time

Most of the time, we find ourselves retreating to the well-lit indoors once the sun goes down. But with a few simple lighting additions, you’ll be able to enjoy evenings outside well into the starlit night, creating a new space to entertain your guests and friends.

 5. Quality

Not all lighting is created equal. You could go to a home improvement store and try to DIY your outdoor lighting, but the quality level and lifetime you’ll receive by going professional is well worth the investment.

Here at Terra Dura, we use Vistapro Landscape LED lights, which last up to 50,000 hours—roughly 50x longer compared to your regular incandescent lights, which last only 1,000 to 2,000. They’ll also use at least 75% less energy.


Here are just a few of the ways professional lighting can enhance your space:



 Pathways: No need to line the edge of your pathway with lights. Try mixing directional path lights with ambient lighting within your landscaped beds for a more natural look.

 Patio: Use diffused down-lighting from above to get a moonlit effect onto your patio.

 Trees: Trees are naturally incredibly beautiful forms to use for up-lighting or cross-lighting.

 Water Features: Underwater lights are both elegant & eye-catching.

 Architectural Elements: Pillars, terraces, and even your home itself can all be lit for dramatic effect.

 Driveway: Consider lighting up the landscaping around your driveway to bring more ambiance for those coming to your home, or for a soothing welcome on your way home from work.


Ready to lighten up? Give us a call at (512) 560-0148 and let Terra Dura Landscapes brighten up your yard to create a relaxing, beautiful, and secure environment for you to enjoy.