According to a facebook science page, this is sand under 250x magnification.

I call BS

Dropbear said:

According to a facebook science page, this is sand under 250x magnification.

I call BS

The magnification looks a little high, but otherwise unsurprising.

No BS. Just depends on where the sand came from. I know a beach in Lombok where close to 100% of the grains are tiny exoskeletons of radiolarians.

Geoff D said:

I know a beach in Lombok where close to 100% of the grains are tiny exoskeletons of radiolarians.

That would be cool.

That should have been foraminifera and radiolarians.

Divine Angel said:

Geoff D said:

I know a beach in Lombok where close to 100% of the grains are tiny exoskeletons of radiolarians.

That would be cool.

It was, Not easy to walk on, however. Like walking on tiny ball bearings.

Geoff D said:

That should have been foraminifera and radiolarians.

Yeah I thought so, I was just about to pick you up on that :)

Well, in all honesty, probably more forams than radiolaria. Ambassador Bill Morrison and his missus were really interested when we visited that beach, because their son was a micropaleontologist in the oil search business at that time.

Not that that really matters, Geoff; just as long as we’re all in agreement that Droppy is wrong, that’s the main thing.

the 250x seems way off IMO

Dropbear said:

the 250x seems way off IMO

Yes. 25X more like it.

Or less … who knows how many times the pic has been re-sized.

Plenty more here – open in new window

I thought beach sand was worn down rock and was mostly silica that you could use to make glass, now youse are telling me its not and that it’s little sea shells that are made of calcium carbonate or some such and that glass doesnt exist.

>The composition of sand is highly variable, depending on the local rock sources and conditions, but the most common constituent of sand in inland continental settings and non-tropical coastal settings is silica (silicon dioxide, or SiO2), usually in the form of quartz.

The second most common form of sand is calcium carbonate, for example aragonite, which has mostly been created, over the past half billion years, by various forms of life, like coral and shellfish. It is, for example, the primary form of sand apparent in areas where reefs have dominated the ecosystem for millions of years, like the Caribbean.

Sand

Peak Warming Man said:

I thought beach sand was worn down rock and was mostly silica that you could use to make glass, now youse are telling me its not and that it’s little sea shells that are made of calcium carbonate or some such and that glass doesnt exist.

On the other (northern) side of Lombok, one beach is completely black. All black mineral grains from the nearby volcano.

I just did a Google image search on sand magnified (because Bubblecar’s link didn’t work for me) and when one link took me to various pictures of magnified sand at different places, the one I picked as what I remember when lying looking at sand on a beach actually turned out to be an Australian one. So I guess I only know the local sand.

Peak Warming Man said:

… and that glass doesnt exist.

It’s a liquid concept…

It’s a liquid concept…

and why the lower you go the thicker the pains.

Geoff D said:

No BS. Just depends on where the sand came from. I know a beach in Lombok where close to 100% of the grains are tiny exoskeletons of radiolarians.

Nice! Rads, I like rads. Now, how did the rads get there? Is there an uplifted bit of non-lithified accretionary wedge nearby? One problem with rads is that if there is pretty much any terrigenous input into the sediment, that terrigenous silt swamps the rads – dilution, if you wish.

Or did you mean something else? Diatoms? Foraminifera?

Michael V said:

Or did you mean something else? Diatoms? Foraminifera?

If you read on, you will find that forams predominate. Also lots of other planktony greeblies washed up in the quiet corners.

http://www.mnhn.fr/mnhn/geo/radworld/genarchaeo/Rectotormentum.html

My favourite rad name…

;)

Geoff D said:

Michael V said:

Or did you mean something else? Diatoms? Foraminifera?

If you read on, you will find that forams predominate. Also lots of other planktony greeblies washed up in the quiet corners.

Oh. I just got to that bit, and asked the question. I’ll continue reading.

Sand is a particle size, not a chemical composition.

South coast of Lombok is a bit special. Big upwelling currents, so great for growing edible seaweed but also great for bringing all sorts of little dead critters onto the shores. And, on the reefs at a special time of the year, the “nyale” (little wormy things that the locals just love).

This is the reef not far from the beach where the strange sand is.

Oh, and one needs to look at the type species for the genus, and how the rather naughty names were justified….

Sorry, didn’‘t realise that piic was going to be so big.

I was going to say the particle size thing, but decided not to be a geotechie just for today.

Dropbear said:

According to a facebook science page, this is sand under 250x magnification.

I call BS

There are quite a few forams in Droppy’s photo (hopefully above this)

Geoff D said:

Sorry, didn’‘t realise that piic was going to be so big.

I was going to say the particle size thing, but decided not to be a geotechie just for today.

It’s interesting how many people think that sand is a chemical or mineralogical description – usually silica or quartz.

Michael V said:

Geoff D said:

Sorry, didn’‘t realise that piic was going to be so big.

I was going to say the particle size thing, but decided not to be a geotechie just for today.

It’s interesting how many people think that sand is a chemical or mineralogical description – usually silica or quartz.

vaginus irratibilus..

So, back to the original question. It is likely fine to medium sand, so the particles are 0.5-0.125 mm across. In the photo, the largest grains ar around 20mm across. So, around 40X magnification is my guess.

So, no comments about the tormentidae, then?

Surprising…

Michael V said:

So, no comments about the tormentidae, then?

Surprising…

The humour is inferred, ergo, no need for further comment :)

Michael V said:

So, no comments about the tormentidae, then?

Surprising…

Not while kii is suffering from morphine induced constipation. Bit inconsiderate to be joking about tormented rectums. ;-P

ergo ipso-facto carpe romanus

Rectotormentum fornicatum = effing good missile stone?

Divine Angel said:

Michael V said:

So, no comments about the tormentidae, then?

Surprising…

The humour is inferred, ergo, no need for further comment :)

Ah!

Geoff D said:

Rectotormentum fornicatum = effing good missile stone?

I’d say!

Michael V said:

Geoff D said:

Rectotormentum fornicatum = effing good missile stone?

I’d say!

Seems the Latin comes out as “vaulted good missile stone” but I refer my earlier rendition.

Droppy,

Did you see that I actually answered your question last night?

Michael V said:

So, back to the original question. It is likely fine to medium sand, so the particles are 0.5-0.125 mm across. In the photo, the largest grains ar around 20mm across. So, around 40X magnification is my guess.