So, I’ve always believed this cube to be made of alabaster or possibly agate, though thinking the former was more likely as it was essentially a tourist souvenir. OTOH, the banding does look very much like agate. But what’s odd here is the weight and size figures above yield a specific gravity of just over 3.0, which is well above that for any of the agate-like varieties of quartz, whose SG normally runs around 2.6, and especially alabaster, which is considerably lighter than agate.
At first I thought the dimensions might be off, but after measuring all of the edges it’s clear all of them measure 6cm, and why not? It’s an inexpensive memento obviously manufactured in thousands, with the measuring, cutting, and finishing obviously done by machine. And by measuring the ruler against a known object, to wit a $5 bill, it should be sufficiently accurate down to the millimeter. Similarly with the scale. I poured .216 liter into a measuring cup, and sure enough the scale read 216 grams. (This scale has a tare button that corrects for the weight of a container).
It sure looks like agate, though. Can my measurements really be that far off? Or is there another kind of decorative stone that looks like agate and has an SG of just over 3.0?
Check the dimensions very carefully , from the picture it looks a mm or so larger . 6.1 on each side gets you a 2.87 g/cc and 6.17 gets to the density of alabaster . Small errors get magnifies as you cube the volume.
Tourmaline has a density of 3.02 but that does not look like tourmaline.
Would alabaster have the closely parallel striations? Also, it’s not easy to see in the picture but the striations run deeply into the mass, rather than being merely superficial. Though, of course, I do realize that alabaster can be translucent, too.
It can do, yes. Banded calcite alabaster is also known as marble-onyx or sometimes erroneously just onyx.
A scratch test would really be able to tell them apart, but IME artifacts of that type are usually coated in hard lacquer or the like, which confounds the testing. But if I were to speculate, I’d say it’s a banded carbonate rather than a banded silicate, as the former is much more common, cheaper and easier to carve. Where it comes from might also be a clue…
And note that another thing that could throw off density calculations a little is the iron content in the bands.
It certainly can do. If you google banded alabaster, you get a whole load of images that contain many quite similar examples (although the bands in yours are flatter/straighter than typical, but still similar to some examples).
I agree. From the picture it looks at least 6.1 cm. (if you re-measure, going across the center of one face might be more accurate than trying to measure an edge)
Or you could accurately measure the volume by displacement of water (might want to put it in a plastic bag and suck the air out so it doesnt soak up water and either get ruined or confound the test.
Unfortunately I don’t have a suitably graduated vessel in which to guage the cube’s volume by displacement–rather just standard food storage containers graded only down to the cup, or 100 ml on the metric side. The measuring cup I mentioned is too narrow for dunking the cube.
Hmmm… perhaps I could fill one of my containers with the cube already in it, remove the cube, then pour the water into the measuring cup and subtracting that number from the container’s volume. I think that would do it.
Rather than finding the volume of the water, wouldn’t using a home digital scale (if you have one) to weigh the water be more accurate? My scale claims an accuracy of ±1 gram.
That could be closer - then you only have to worry about a measurement error scaling 1 to 1 rather than as a cube function.
That said - the error was only 2.7% on the length that gets you from - clearly Alabaster to WTF is this stuff?
If the true density is 3.0gcc then you would have a volume of 217 cc , if it is 2.7 gcc then you will have a vol of 241 gcc. so your pouring needs to be able to clearly distinguishes between 24 ml
That could be tough looking at a measuring jug graduated in 100 ml intervals.
But there is hope if you think about the test you did to verify the scales.
Do the following .
fill up a beaker with water large enough to put on the scales
put it on the scales, don’t worry about the tarre / zeroing yet
drop the cube of mysterium into it
mark the level of the water - use a really thin line or note if the line top or bottom is water level, go to the bottom of the meniscus ( the curve of the water up the side of the beaker)
remove the block of mysterium and allow as much water as you can to drain back into the beaker.
Zero your scale
with what ever method you have slowly and carefully add water back until the water level is back up to the line you drew, you can probably pour at the beginning and use a teaspoon at he end
when the water is back to the line look at the mass
Given we are pretty certain of the density of water, based on the mass of water added to get back to the line, we know the volume of water added.
I do have the scale and agree it would be easier to determine the change in the water’s volume by weighing the remainder. As I mentioned, the scale has a tare adjustment feature so it’s simple to use a second container on the scale.
To all: Can I really damage this object by a few seconds of immersion, even if I vigorously towel it off immediately atterwards?
You should see how clumsily I wrap a large, blocky package for Christmas or someone’s birthday, though seemingly it should be the easiest type of package to wrap.
Anyway, I’ve now basically used Rowrrbazzle’s basic approach by placing the well-wrapped cube into a pre-marked 750cc container, and adding water up to .750l mark including the immersed cube. After removing the cube, reweighing the container and remaining water, and allowing for the tare weight of 39g, I calculated as follows:
and got…curiously enough…er…217g of water displaced! Again, this doesn’t surprise me too much, because I’m sure the cube was meant to be 6cm on an edge and having been manufactured by machine, it has very little reason to be anything else. It’s not as if it was made by some master stone-worker with hand tools and a jeweler’s loupe.
In case anyone’s curious, the cube root of 217 turns out to be just a kitten-whisker less than 6.01.
Well not chalcedony type of onyx, not the silicate relative of agate…
Thats formed in lava or vulcanism, and occurs as bubbled and balls as the heat and pressure conditions are never consistent.
Meanwhile alabaster ,a type of coloured marble, was formed by layers of limestone depositing… when that occurs in the bed of a sea or lake, the layers can be so thin and parallel …
