A microscopic look at why the world is running out of sand

A microscopic look at why the world is running out of sand

(staccato synth music) – [William] This is
sand under a microscope. But, so is this, and this, and this. Sand isn’t one thing,
it’s incredibly diverse. And all its differences
have global significance. We’re on a sand scavenger hunt. We’re collecting samples
and we’re gonna send them to Cory in New York to
look at under a microscope. And we’re doing all this because sand is actually one of the most critical natural resources there is. It has a million different uses, but it’s a crucial component of concrete and humans use more concrete than any other material besides water. It’s fueling these huge construction booms in places like India,
China, and parts of the U.S. And you might have seen news about the world running out of sand. That’s true, but it’s not that simple. The future of construction
actually depends on the science of each
tiny little grain of sand. (car engine starts) First off, the definition
of sand is really broad. It can be made out of any
kind of rock or mineral. Really, what makes sand sand is size. Each grain is somewhere
between 0.05 millimeters and two millimeters across. Smaller than that, and it’s silt, larger, and it’s gravel, that’s kinda it. But what sand is made
out of, where it’s from, what it’s shaped like,
all of that is important if you wanna build with it. The basic recipe for
concrete is pretty simple. Sand and other large rocks
get mixed together with water and cement, which is a
powdered binding agent commonly made from limestones and clays. The cement solidifies with the sand and rock particles to form concrete. And what you really want
for concrete is river sand. The grains are rounded and
their size is consistent. That helps the sand bind with the cement. It’s also made with a nice
hard mineral like quartz without too many softer minerals mixed in. And river sand, really good river sand, ticks all of those boxes because of this incredible
journey it goes on. – Think about the individual grain of sand that was once on the mountaintop – [William] That’s Frank
Leith, a geology expert at a sand producing company
called Vulcan Materials. Basically, the sand in
the Sacramento River here started up to 400 miles away,
around the Klamath mountains of northern California. Very slowly over time, little
jagged bits of those mountains chipped off by freezing,
thawing, rain, wind, – Fell down into the canyons
and then fell into the rivers. In the rivers themselves,
once they’re underwater they’re being transported and
bouncing against each other hitting each other millions of
times or more, and impacting, and knocking all the corners
off of that angular grain of material that fell down. – [William] Along the way, softer minerals are slowly dissolving away
so that, after 400 miles, you get this, what, in lots of situations, is the ideal sand for concrete. Of course, river sand ends
up somewhere too, the beach. It’s maybe the most
mature sand that there is because once a river
deposits it on the beach, it gets continually worked
and reworked by wave action. But, beach sand comes with its own issues It’s salty, which can
mess with the chemistry of the concrete mix, and it’s less pure. There are lots of shells
and bits of sea-life and who knows what else. That can make the concrete
softer, or chemically reactive. You can fix both those things,
but the concrete might be more expensive or trickier to work with. So, that’s beach sand. (engine starts, light guitar music) There’s one other kind of sand we wanted to compare, manufactured sand. Which is, basically what it sounds like. – Making small rocks out of big rocks. – [William] Crushed sand is
trickier than natural sand because it doesn’t go through that natural weathering process so it’s very sharp and angular. But unlike river sand,
we don’t have to wait for mountains to weather
down over millions of years, we can make it ourselves. (cars driving by) So we got some of that too. They wouldn’t let us
film inside the quarry but they gave us a very large sample. (car door opens) (staccato synth notes) River, and manufactured
sand are pretty different, but they both solve the other
huge driver of sand scarcity. Sand is cheap to produce
but bulky and heavy to ship. Frank says transportation
of sand can cost them two to four times more than production. So, sand usually stays local. – [Frank] You know, when you
see an average dump truck that’s driving down the road with material it’s probably not going
more than 30 or 50 miles from the source of where
it got its material. – [William] Any farther than that, and it’s probably not
worth the cost to move it. Rivers are so useful because
they cover a lot of ground and quarries can create in lots of places. Both of them allow builders to
collect and use sand locally. When you don’t have ideal sand
nearby, scarcity gets scary. And in the short term, that’s what ‘we’re running out of sand’ really means. There just isn’t enough sand
in the places we need it most. That’s where you get these
reports of sand mafias in India, stealing entire riverbeds
to meet massive demand or some construction projects in Dubai that have resorted to shipping sand in from place like Australia. Dubai is surrounded by desert sand, but it’s actually too fine and smooth to work well in concrete. Again, you need the right sand in the right place for the right job. (staccato synth notes) So, how’d we do? Well, we sent the samples to Cory, he got them all organized and imaged and we saw a lot. We called Frank back to get his take. – [Frank] The manufactured
sand popped right out I mean there’s just corners
and angles everywhere which really shows how fresh and young that manufactured sand is relative to the, to the
other sands that you sampled. – [William] Frank saw a big contrast between the manufactured sample, and both the photos of
river sand that we sent him. – [Frank] Both of them have
a very high concentration of, of rounded quartz grains. – [William] It’s those
smooth quartz grains that work so well in concrete. As to the beach sand, the
grains were nice and round, but there were more mystery
grains in there too. Like this big blue-green
one in the middle. – [Frank] One possibility
is, this is a tourmaline, it’s also found in some
of your heavier minerals. – [William] All in all,
we did pretty well. But of course, it’s so
much more complicated. In reality, each one of those
grains went on its own journey so even within a single sample,
collected from one place, there’s a whole world of sand represented. – [Frank] Uh, in geology
there’s, there’s never a, there’s never a perfect
story, it’s always a, there’s always some
additional detective work that has to be done. – So listen, there’s a whole
other part of the story we didn’t talk about, and that’s the environmental impact of doing all of this sand harvesting,
all around the world. That’s real, we just didn’t
have time to talk about it in this video but hopefully
we’ll cover that soon.

99 thoughts on “A microscopic look at why the world is running out of sand

  1. Sorry but we won't ever run our of sand, when I see deserts go up then I'll believe. I don't think they are under threat as of yet. Running out of sand lol ya

  2. I’m an intern in a frac sand lab so I was mostly just watching this video to see how accurate it would be lol. You want different properties for frac sand than you do in concrete sand but Y’all did a good job here though 👍

  3. Now, this is just my idea for a solution to the manufactured sand problem.

    Why not just invest in large tumblers, effectively huge industrial washing machines. You throw in small, roughly similarly-sized gravel stones, and leave it to tumble for a variable amount of time – however long you need for the amount and how fine. It replicates most conditions of the mountain rivers, and solves the problem. Sure, we'd be spending money on it, and my idea definetly would need to have more development and expansion for proper wide use – but, it's just food for thought.

  4. So it isn’t that sand is running out, so much as it is the sands specifically needed for human construction thats running out?

  5. 7:00 -tall gangster quartz grain wearing shades. Staying on the DL, trying to blend in with the rest of the grains…

  6. I guess no one in this video has come by KS. We in my area, have extremely sandy soils. The area is so much sand we have numerous companies with sand and rock extraction quarries or as we call them sand pits.

  7. I'm confused about why the folks in Dubai couldn't just filter out the particles of local sand that were the right size. I thought desert sand was all blown around and rounded as well…seems like there's something I may not understand about this situation.

  8. I watched this twice – the second time on 50% speed paying very careful attention to the parts showing the microscope in action and I am just not seeing/hearing the part where the microscope is showing us WHY the world is running out of sand as your title says.

  9. Violently wakes wife at 3 am SWEETY WE NEED TO GO TO HOME DEPOT FOR SANDBAGS RIGHT NOW wife: wat are talking about slaps wife THERE’S NO TIME

  10. u can go to any beech around the world and come home and big brother can know what beech u were at, just by looking at the sand on your shoe under a microscope!

  11. So the theory about how all the sand we have mined and are mining especially from the ocean floor is effecting plate movement and may help contribute to Earthquake and other end of the world disasters holds some serious weight when you really think of how much building humanity has done, is doing, and will do with sand…




  13. Worker1: hey, what did you give to that person?

    Worker2: I gave him a large sample of our manufactured sand

    Worker3: hey guys where is the weed?

  14. i think the solution to this is to ramp up the process of manufacturing sand and improve the quality of manufactured sand. it seems like we just need to process it more thoroughly to get better results

  15. This is too funny. Beach sand has salt which might mess with the cement. Hummmm … the Romans made concrete with salt water and their concrete has lasted MUCH longer then our modern concrete does and ever will.

  16. Here where I live somebody stole a not so big sand dune near the beach. It took them 3 weeks to take small truck loads away on a daily basis.

  17. The world isn’t running out of anything it’s quite literally impossible the problem is there are too many people there’s not supposed to be this many people

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