Volcanic sand

[roridula]

I've obtained some volcanic sand, a fine dark-colored sand. The bag indicates its use as a soil amendment, presumably for orchids or African violets. It mixes well with peat. Does anyone have experience with this for CP use and can confirm it does not have hidden lethal attributes?

[Deleted]

i dont think it would be a problem but im not an expert so dont use it just cause i think it wont

[BarryRice]

Hey Roridula,

Interesting. So does it appear to be finely crushed obsidian?

If it is obsidian, it should be entirely neutral in its chemical characteristics. HOWEVER, it might have been harvested from black sand beaches, in which case it would be wise to wash it thoroughly to remove sea salt.

Barry

[Deleted]

see barry is smart ...lol i never even thought about the fact that its obsidian which is pretty much little pieces of glass so it owuldnt have nutrients really...but yeah if it is collected from a beach the salts in it could be harmfull.........its sort of hard tho to wash sand......good luck

[zpyder]

Washing sand when I worked at an aquatics shop wasn't too bad, you just used a hose on a jet mode to blast it a dozen times and mixed it with hands. The abrasive action of the sand helped clean itself. Of course though, with CP's it might be a different story if they're likely to be sensitive to tap water?

I'm not a geologist, so please do correct me, but could volcanic sand also contain minerals and elements? For some reason I'm thinking of some "volcanic" rocks that contained different metals and stuff, and were really sharp. However these may have been man-made rocks from slag, I'm not sure?

[Not a Number]

If it is beach sand from Hawaii I would eye it with suspicion as removal of sand from the black sand beaches is prohibited. As I recall the sand is relatively "sharp" as beach sand goes.

[Deleted]

lol yeah if its pretty much smashed obsidian ....i would hate to get a grain of it in my eye

[kulamauiman]

could it be crushed basalt? That was gonna be my first question. Quartz sand is a bit hard to come by here in Hawaii. Was wondering if basalt crushed fine would work. It is also originally of volcanic origin also. Least here in Hawaii. Do have the red and black lava rocks (volcanic cinders) that work well for other plants (orchids and anthuriums) that can be found with a coarser grade. Any suggestions?

Mahalo,
MTF

[timpa]

Hi Roridula,

I've never used this stuff, so I'm just guesing here. I'd doubt that it's crushed obsidian. Obsidian's relatively scarce and the gem shops gobble it up. It's most likely crushed basalt, which is much more common.

Either way it could be bad news for your CPs. Both basalt and obsidian react with water and various organic acids to liberate metallic ions, most notably Na, Ca, Fe and Mg. And those can play merry hob with the roots of your CPs.

Of course, they could be fine. If it's fresh basalt or obsidian that cooled rapidly then it'll be relatively inert and probably wouldn't be a problem, especially if you top water and have continuous water flow to remove any salts produced. On the other hand, if the stuff has been sitting around on a beach for ages (likely since this is the cheapest and most abundant source of basaltic sand) it is most likely already moderately weathered and will release salts pretty rapidly.

The simple way to find out is to chuck a handful in a jar and add purified water to make a mush. Seal the jar and leave sitting for a month or two in your terrarium and them check the dissolved solids in the water.

[Randy Zerr]

Personally I wouldn't bother with it other than an experiment to see what would happen. Volcanic soils are noted for being very rich in minerals. I studied chemistry some and agree with what timpa said, If mixed with peat moss, over time the natural acidity would begin to react with and iron, sodium, calcium and other natural mineral components of the sand and salts would result and may or may not affect the plants. It seems quartz or mostly quartz sand is available anywhere? If not available, I might be able to ship 50 lbs or less some pure white quartz sand. It's all we have here in the Florida panhandle, even well inland from the beach. The cost for UPS would be high though.
When I lived in northern Louisiana some soil experiments were done with tuberous and pygmy Drosera with locally abundant "laterite" gravel as described in the natural habitats in Allen Lowrie's books "Carnivorous Plants of Australia" . Pebbles of different sizes of limonite and other hydrated iron oxide minerals mixed with quartz and probably other mineral sand stained rust. The CPs grew in it. But they also seemed to do just the same in regular peat/sand mix. The laterite gravel made a very attractive top dressing though

[Vater Araignee]

Apr 29, 2008 4:10:57 GMT Randy Zerr said:

I might be able to ship 50 lbs or less some pure white quartz sand. It's all we have here in the Florida panhandle, even well inland from the beach. The cost for UPS would be high though.

Then use USPS.
Priority Mail Large Flat Rate Box
12” x 12” x 5.5”
$12.95
Up to 70 pounds
The contents of the flat rate box must be neatly contained inside the box with adhesive packaging tape.
The box must close securely and retain its shape when taped with adhesive.
The shape of the box may not be changed or enlarged to fit its contents.
USPS.COM
You can order as little as one pack of ten and it will be delivered to you free of charge and you don't pay till you ship.

If you decide to find out how many pounds of sand they hold, let us know.

[ICPS-bob]

According to
www.reade.com/Particle_Briefings/spec_gra2.html
Quartz sand weighs 70 pounds/cubic foot. Or, "sand, dry" weighs 100 pounds/cubic foot. So a package 12” x 12” x 5.5” filled with sand would weigh between 34 and 46 pounds.

[Vater Araignee]

Jun 9, 2008 19:00:55 GMT ICPS-bob said:

According to
www.reade.com/Particle_Briefings/spec_gra2.html
Quartz sand weighs 70 pounds/cubic foot. Or, "sand, dry" weighs 100 pounds/cubic foot. So a package 12” x 12” x 5.5” filled with sand would weigh between 34 and 46 pounds.

But wouldn't a finer grade of sand be heaver in the same space vs. a coarse grain sand? <-- moot question.

Based on ICPS-bob's figures I would send shipping and time compensation for some of that silver sand.