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[Uristocrat]

The data from the V3 raws has been encorporated into Dwarf Fortress 0.34.08.  Thanks, everyone!

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News from the Devlog:

05/11/2012 Toady One We finally nabbed the bug that was intermittently hanging the game. I've incorporated some fan-collected material numbers that came out of an effort spearheaded by Uristocrat.

I believe that Toady is incorporating the data in the V3 raws, in case we find more data and publish an updated version someday.

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I suggest we add solid density information for all the various kinds of rocks.  That way, they won't all be exactly the same when used in rockfall traps and catapults.  Also, it changes their in-game weight (and thereby the speed at which they're hauled) and a few other things.  Here's the data.  The data is also in RAW file form.  People are encouraged to use my mod and the data freely.

Latest RAWS - Currently at V3, which corrects a couple of minor errors in the V2 raws based on better research.

See also: NW_Kohaku's Geology Thread

NEWEST:  My prior source on electrum looks a bit sketchy in hindsight.  Dr. Luuvalo, who knows a lot about metals, taught me a lot.  We believe that a weighted average of gold + silver's density is likely to produce a more accurate density.  This appears to be born out by this Google books result, which lists a range of 13000-16000.  Because DF models electrum as 50% silver + 50% gold in its recipe (the actual proportions vary quite a bit, per wikipedia's article on electrum and may even include copper), I think the best density value for DF's electrum is (19320 (gold) + 10490 (silver)) / 2 = 14905.

NEW:  The guesstimate of 300 kg/m^3 for Saguaro density in the V2 raws was probably wrong.  I have a 6g piece of Saguaro wood with a volume of approximately 14 cm^3, which indicates that the density of Saguaro wood is approximately 430 kg/m^3.  This number appears very reasonable when compared to all the other densities I have researched.  I have more ~1 ft pieces of Saguaro rib wood than I know what to do with right now and I'm more than willing to ship them to people willing to do further research on the matter, or those who wish to duplicate my experiments.

I'll issue a V3 raw with this corrected eventually, but I will probably wait to see if more data can be obtained first.

BishopX was kind enough to point me to MatWeb.  They seem to have a lot of information, but most of it is for modern alloys and whatnot.  Still, I'm including it here in case we can find something useful there.

If you have any questions about my sources, please ask.  I tried to link up most of them, and even more are in the RAWs proper, but a lot of that gem data was either from CSG Network or GemSelect, occasionally supplemented by Wolfram Alpha, as I recall.

Wood data (densities & colors) is now in those V2 raws, but I haven't put anything into this thread yet.  Most of it was taken from the Forest Products Laboratory, a division of the US Forest Service (and their website is back up now).  Another good source of wood data is this site.

Here are the V2 RAWs.  You can still get the V1 RAWs if you want them for some reason.  People who understand mechanical properties like impact fracture are encouraged to comment here.  I have a lot of new structural data for wood and a lot of questions about how to help DF make use of it.

NEW!  We now have a source of data for wood too.  Yes, wood.  How did I find that?  Looking up the Sandbox tree (the one with explosive fruit...).  See for yourself just how much detail we can get:  density, bending strength,  modulus of elasticity, maximum crushing strength, ... oh yeah.  Fun with training weapons maybe?  I wonder....  There are LOTS of different woods in there to look up, too.  We should be able to put in realistic values for all kinds of woods, so that all the woods in the game aren't nearly identical.

OTHER DATA:  Anyone who can find other sources of material data for me to look at is encouraged to post them in this thread.

When looking up densities, I suggest that you search for "specific gravity" instead of density.  You get much better results.  The value DF uses is specific gravity * 1000, so it's pretty easy to convert (e.g. a S.G. of 2.6 == 2600 in DF).

I found a MUCH better source on soil density.  I plan to update my raws with this data soon.  Yes, that website sounds weird.  I didn't name it.  It gives you a lovely calculator for soil density, though.  Contrary to how I deal with rocks, it seems that "bulk density" (not specific gravity) is a more reasonable measure.  Otherwise, we ignore the fact that the soils have a lot of air.  I think that undersea soils, due to compaction from the water, are a bit denser, though.

Wolfram Alpha is one good source of density information, but it likes to give me g/cm³ instead of kg/m³.  All I have to do is multiply that by 1000 to convert it.  You can also take the specific gravity and multiply that by 1000 (and specific gravity is easier to search for).

NOTE:  For comparison, all non-ore rocks appear to be at the current default density of 2670 kg/m³.

Stone Density Data:

Mineral	Solid Density (kg/m3)	Sources / Notes
Alabaster	2300	Wolfram Alpha (same as Gypsum)
Alunite	2745	Wolfram Alpha
Andesite	2430	Wolfram Alpha
Anhydrite	2960	Wolfram Alpha
Basalt	2850	Wolfram Alpha
Bauxite	3100	Minerals Zone
Bismuthinite	7000	Wolfram Alpha
Bituminous coal	1350	Wolfram Alpha
Borax	1730	Wolfram Alpha
Brimstone	2070	No clue what "monoclinic sulfur" is so used the other density from Wolfram Alpha
Calcite	2930	Wolfram Alpha
Cassiterite	6900	Wolfram Alpha
Chalk	2710	Wolfram Alpha
Chert	2650	Wolfram Alpha
Chromite	4795	Wolfram Alpha (Search for the mineral not the ion)
Cinnabar	8100	Wolfram Alpha (Search for the mineral, not the word)
Claystone	2700	Mentioned in The later Proterozoic Torridonian rocks of Scotland: their sedimentology By A. D. Stewart; a Google books result.
Cobaltite	6330	Wolfram Alpha
Conglomerate	2000	Answerbag says it's 1700-2300, used the middle of the range given.
Cryolite	2975	Wolfram Alpha
Dacite	2400	Gerlach lists dacite density as 2.4*1012 kg/km3, which I let Google convert for me.
Diorite	2870	Wolfram Alpha
Dolomite	2850	Wolfram Alpha
Gabbro	2920	Wolfram Alpha
Garnierite	2540	Webmineral
Gneiss	2800	Wolfram Alpha
Granite	2600	Wolfram Alpha
Graphite	2250	Wolfram Alpha (Search for the material)
Gypsum	2300	Wolfram Alpha (Lists data for Alabaster; used that.)
Hornblende	3235	Wolfram Alpha (Search for it as a mineral)
Ilmenite	4720	Wolfram Alpha
Jet	1320	Calculated based on the specific gravity listed on Wikipedia.  Middle of the range of 1300-1340 was chosen.
Kaolinite	2600	Wolfram Alpha
Kimberlite	2540	Geophysical Characteristics of Canadian Kimberlites  (Chose the median value from Table 1)
Lignite	1250	Wolfram Alpha
Limestone	2710	Wolfram Alpha
Limonite	3500	Mindat.  Gives a range of 2700-4300, took the middle of the range
Malachite	3800	Wolfram Alpha
Marble	2780	Wolfram Alpha
Marcasite	4890	Wolfram Alpha
Mica	2883	Simetric.  Used the "solid" value.
Microcline	2560	Wolfram Alpha
Mudstone	2250	Wolfram Alpha says it's the same as shale
Obsidian	2650	Cochise College gives the specific gravity as 2.6-2.7, so I converted and averaged that.  Real values should be variable, depending on trapped gasses.
Olivine	3320	Wolfram Alpha
Orpiment	4250	Wolfram Alpha
Orthoclase	2560	Mindat & Wolfram Alpha
Periclase	3785	Wolfram Alpha
Petrified wood	2200	HPWT, chose the middle of the 1900-2500 range.
Phyllite	2800	Geophysical Field Pattern in The West Bohemian Geodynamic Active Area (PDF), mentions "dense Ordovician phyllites."
Pitchblende	7600	The Free Dictionary, gives a range of 6000-9200, depending on the UO2:UO3 ratio.  Middle of range was chosen.
Puddingstone	2000	No source found. It's a type of conglomerate, so I used that value.
Pyrolusite	4730	Wolfram Alpha
Quartzite	2600	Wolfram Alpha
Realgar	3560	Wolfram Alpha
Rhyolite	2600	University of Colorado GEO 1010 gives a range of 2500-2700, chose center.
Rock salt	2170	Wolfram Alpha (Search for it as a mineral)
Rutile	4250	Wolfram Alpha (Search for it as a mineral)
Saltpeter	2105	Wolfram Alpha (Search for it as a mineral)
Sandstone	2400	Wolfram Alpha
Satinspar	2300	Wikipedia; same as Selenite
Schist	2900	Wolfram Alpha
Selenite	2300	Wikipedia; same as Satinspar
Serpentine	2450	Wolfram Alpha
Shale	2250	Same as mudstone.  Source Wolfram Alpha
Siltstone	2500	Assumed it was a slightly denser sandstone.  If you want to download a 16MB PDF of some book to hunt for a better value, try The Petrology of Sedimentary Rocks
Slate	2750	Wolfram Alpha
Sphalerite	4050	Wolfram Alpha
Stibnite	4630	Wolfram Alpha
Sylvite	1990	Wolfram Alpha
Talc	2710	Wolfram Alpha
Tetrahedrite	4900	Wolfram Alpha

NOTES:  Some of these were already in the raws (e.g. cobaltite).  But my raws differentiate lignite from bituminous coal and correct the density of several minerals like ilmenite which were in the raws, but which had incorrect values.  My raws have notes of the values I changed.

My raws also correct the layers the gem tanzanite appears in.  It (which should occur in metamorphic rocks, not gabbro.  The raws mentioned uncertainty, but it's definitely not the same as peridot.  It should also be rare, but I didn't change that.  IRL, tanzanite is only found in one place in the world.

I found some very different data for the gypsum related minerals.  I'm getting them all at the same density, except for anhydrite, which is a lot more dense than the others and I've consulted several different sources to check.  The value already in there was too high and looked more like a value for anhydrite.  If anyone wants to do more research, I suggest trying to find good average values for things with huge ranges (like pitchblende) or good data to differentiate the gemstones (the garnet group, in particular, has a big range and it's not clear where all of the members should fall in that range).

I made a broad categorization for gems, too.  I don't know if this is useful, but maybe it could be used to simplify things.  Some of the uncategorized gems might fit in the classifications given.  I didn't research that, but maybe I should.  Most of this comes from this great source for gem data.  If you notice, that table is properly colored, too, based on the gem's color.  Most of my color research, though, was based on going to Google Image Search and typing in the gem name.  You do have to be careful to make sure you're getting a picture of the right gem, though, in a few cases.

Here's another nice list of gem properties with a lot of specific gravities for use.

Gem Data:

CLASS	GEMS	DENSITY
BERYLS	Beryls, heliodor, aquamarine, emerald, goshenite, morganite	2770 (2630-2910)
CHRYSOBERYLS	Chrysoberyl, alexandrite, cat's eye	3730 (3680-3780)
CORUNDUMS	Ruby, sapphire	4005 (3960-4050)
DIAMONDS	Diamonds	3520
FELDSPARS	Moonstone, Sunstone	2655 (2550-2760)
GARNETS	Garnets, pyropes, melanite, demantoid, topazolite, grossulars / tsavorite, almandine, rhodolite, spessartines	3900 (3500-4300)
JADES	Jades	3000 (2900-3100)
OPALS	Opals	2115 (1980-2250)
QUARTZ	Amethyst, agates, aventurine, bloodstone, carnelian, citrine, chalcedonies, chrysoprase, jaspers, morion, onyx, prase, quartzes, sard, sardonyx, tiger eye, tiger iron	2650
SPINELS	Spinels, rubicelle	3820 (3580-4060)
TOURMALINES	Tourmalines, schorl	3140 (3030-3250)
ZIRCONS	Zircons	4650 (4600-4700)
UNCATEGORIZED	Schorl, variscite, chrysocolla, pyrite, peridot, tanzanite, kunzite	(see below)

Uncategorized Gems:

GEM	DENSITY
Variscite	2510
Chrysocolla	2150
Pyrite	4890
Peridot	3335 (3220-3450)
Tanzanite	3350 (3200-3400)
Turquoise - (NOT CURRENTLY IN GAME)	2700 (2600-2800)
Kunzite	3150

EDIT:  Moved tiger iron to the quartz group and schorl to the tourmaline group.  It might be worth adding turquoise as a gem; I honestly didn't realize that it wasn't in the game already.  Credit for that goes to Shinziril, who posted it in this thread.

Colors are weird.  On one hand, some of those in game aren't too reasonable (cobaltite is not actually blue, it's greyish-silver, like iron, zinc, etc.), even though there is a cobalt blue pigment.  Bismuth is the same.  Yes, it can look purple, depending on the light.  My sample really looks light blue to silver most of the time, though.  And bloodstone, in spite of what you might think based on the name, is dark green for the most part (though it has deep red bands).  And I don't even know how to represent opals, given that they have every color in them, though I guess most of them should be white or clear.

So feedback on the colors I put into those raws is appreciated.

[Kogut]

Suggestion: produce diff to RAWs and post it on mantis.

[Uristocrat]

SOIL DATA

EDIT:  This post was unimportant.  I'm modifying it to have a place to put all the soil density data I found.

I had soil densities before, based on a really simple model I made (which was actually pretty accurate!), but now I've found a much better source.  DF soil classifications are based on something called a texture triangle.  It's kind of confusing:  you click on that image, and it calculates values for you.  If you're wondering about the URL, I have *no* idea why they named their site that, but the information is great.

I actually used this tool from the same site to get this data, though.  It lets me plug in sand/clay/silt percentages to get a density value (loam, if you're wondering, is a roughly-equal mix of all three of those), then tells you what sort of soil that is and what its bulk density is.  It won't let you have things like 100% clay, though, but that's okay:  that wouldn't be very realistic, anyhow.  Fire clay is somewhat closer to pure clay, but I took that density from elsewhere.

Soil Name	Bulk Density (kg/m3)	Sand %	Clay %	Silt %
Clay	1210	20	60	20
Silty Clay	1210	5	50	45
Sandy Clay	1330	55	40	5
Clay Loam	1320	33	34	33
Sandy Clay Loam	1410	60	25	15
Silty Clay Loam	1290	10	30	60
Loam	1410	40	20	40
Sandy Loam	1560	65	10	25
Silt Loam	1410	20	15	65
Loamy Sand	1690	80	5	15
Silt	1450	10	10	80
Sand (all colors)	1710	90	5	5

I would actually like to differentiate the sand there, but they're based on color, not material.  Do I assume that black sand is volcanic sand, or iron-bearing sand?  Here are the other soils:

Soil Name	Density (kg/m3)
Peat	850
Pelagic Clay	2200
Calcareous Ooze	2690
Siliceous Ooze	2460
Fire Clay	2300

The value for peat comes from here and assumes some water content.  Maybe I should assume a peat bog where it's completely wet and bump that up to 1100 or something.  I don't know.  Fire clay comes from the same site (I think it's supposed to be a heavier clay, which isn't on that texture triangle).  The undersea soil data is from something called Geotechnical Properties of Deep Continental Margin Soils (PDF warning).

[Uristocrat]

Wood Data

I never did put the wood data into a thread.  This post was unimportant, so I'm editing it to be the wood data now.

Tree	Density (kg/m3)	Species Used as Basis	Source
Mangrove	830	Black mangrove (Avicennia spp.)	US Forest Service
Saguaro	430	Carnegiea gigantea	(Determined empirically)
Pine	510	Red Pine (Pinus resinosa)	US Forest Service
Cedar	570	White-Cedar (Tabebuia spp.)	US Forest Service
Oak	700	Encino Oak (Quercus spp.)	US Forest Service
Mahogany	600	African Mahogany (Khaya grandifoliola & K. senegalensis)	US Forest Service
Acacia	600	Acacia mollissima syn. A. mearnsii	US Forest Service
Kapok	260	Cieba pentandra	US Forest Service
Maple	540	Acer spp.	US Forest Service
Willow	390	Black willow (Salix nigra)	US Forest Service
Larch	590	Western Larch (Larix occidentalis)	US Forest Service
Chestnut	430	American Chestnut (Castanea dentata)	US Forest Service
Alder	410 (450 might have been a better choice)	Red Alder (Alnus rubra)	AHEC
Birch	650	American Birch (Betula spp.)	US Forest Service
Ash	600	Fraxinus spp.	US Forest Service
Candlenut	140	Aleurites moluccana	The Wood Explorer
Mango	520	Mangifera spp.	US Forest Service
Rubber	490	Hevea brasiliensis	US Forest Service
Cacao	430	Theobroma cacao	Inpa.Gov.BR
Palm	680	Red Palm (Cocos nucifera)	Wood Database

There are also colors in the raws.  For example, cacao wood is labeled as "chocolate" ... which is actually accurate, IRL   The experiment determining the density of Saguaro wood was determined by finding that a 6g (+/- 0.1g) piece of dry Saguaro wood had a volume of approximately 14 cm^3 (+/- 1 cm^3), leading to the conclusion that Saguaro wood has a density of approximately 430 kg/m³.  Samples of the wood are available upon request for anyone who wants to attempt to duplicate these results.

[FGK dwarf]

Interesting stuff! Couple of comments:

For sulphur/brimstone, monoclinic/rhombic refers to the crystal structure. rhombic is the stable allotrope at room temperature and pressure according to wiki, so you chose the right value.

However, the density doesn't always take into account any large holes in the rock or mineral. I used to have some sulphur and remember there being big gaps between the crystals, making it quite crumbly, so the value for a big chunk like the Dwarves would mine may be somewhat lower. Same goes for other pure minerals. Rocks tend to have fewer holes as they're formed of many minerals squashed together.

Conglomerate is made of of other rocks cemented together, so it's density probably varies so much because its composition can vary.

Wiki gives the specific gravity of jet as 1.30 to 1.34, a little higher than lignite, probably becasue jet is formed under higher pressure, like bituminous coal.

[Jeoshua]

I would love to see more realistic stone values.

As a matter of fact... thank you for gathering this into one place, I'm going to mod it in to my raws right now!

[Kogut]

I would love to see more realistic stone values.

As a matter of fact... thank you for gathering this into one place, I'm going to mod it in to my raws right now!

And you will post resulting file and diff, right?

[Uristocrat]

Conglomerate is made of of other rocks cemented together, so it's density probably varies so much because its composition can vary.

Wiki gives the specific gravity of jet as 1.30 to 1.34, a little higher than lignite, probably becasue jet is formed under higher pressure, like bituminous coal.

I fixed that per your comment.  Pitchblende, though, is the *really* variable one, going from ~6000-9000.  I wonder if just splitting the difference like that gives a good average?  And whether my guess about siltstone was reasonable or not.

[NW_Kohaku]

That's fantastic, Uristocrat.  People doing research to flesh out the raws is exactly what we need more of to help iron out the kinks in this game...

I'm surprised how much of a difference there is in these numbers - sylvite has about a quarter the density of cinnibar, which is the sort of thing you wouldn't expect to see.

[Uristocrat]

That's fantastic, Uristocrat.  People doing research to flesh out the raws is exactly what we need more of to help iron out the kinks in this game...

I'm surprised how much of a difference there is in these numbers - sylvite has about a quarter the density of cinnibar, which is the sort of thing you wouldn't expect to see.

Yeah, I also learned that cobaltite is already in the raws as something pretty dense, so it's a great thing to lob at goblins, at least if you don't mind using up your dark blue stone   *sigh*  So there are still trade-offs between aesthetically pleasing fortresses and goblin crushing ability.

I've also noticed (via speedhack dwarves) that the weight *really* changes the hauling speed (it might not be as bad for non-speedhack dwarves, though).  The suckers really lag when hauling gold (which is, again, already in the raws) vs. normal stone.  So this should be interesting in other ways, too.

Are there any other material values with significant gameplay effects that we should research?

Also, I looked up another source for pitchblende (err, uraninite, UO₂, actually), which gives a specific gravity of 6.5-10.0 (so, a density of 6,500 - 10,000).  They really can't pin it down much, huh?  Meanwhile, that same source (a RL book) gives rutile as exactly 4.23, which is in close agreement with the 4250 I already have listed.

[Rose]

This is a fine list. good work.

[Fayrik]

Now, I might be wrong here but...
You're trying to add "Realistic density values" to DF, right?
...But, from the admittedly limited amount of time I worked on DF's solid density, they seemed pretty accurate already.
Maybe I just missed something?

[Uristocrat]

Now, I might be wrong here but...
You're trying to add "Realistic density values" to DF, right?
...But, from the admittedly limited amount of time I worked on DF's solid density, they seemed pretty accurate already.
Maybe I just missed something?

Most of those are set to a default value for rock of 2670 right now.  If you scan the list, you'll see that it's pretty reasonable for many of the rocks, but a pretty bad estimate for the rest.

That said, it still needs some double-checking to make sure it accounts for *all* of the materials with no values set.

I'm betting there are other things, perhaps including non-stone objects that may or may not have proper values right now.  Most of the material properties only matter for weapons, though, which is why the metals and metal ores got all the attention.  Of course, as I pointed out, we *do* use rocks as weapons in catapults and stonefall traps, so maybe we should take a look at whatever other values need adding.

[NW_Kohaku]

When it's a wide ranging estimate like 6,500 to 10,000, I'd probably err towards the average density of stone in general - odds are this isn't pure ore, and as such, should probably have a little fudging towards the density of the other materials it would likely be mixed with. 

A wide estimate like 6,500 to 10,000 probably means there are varying levels of how much uranium is actually in those uranium-oxide compounds, and Uranium is extremely dense, but also very rare stuff in any form of concentrated quantity.

As for "what other properties are important", I'd have to go back and look at what properties are useful, ever, in the metals section. 

Flint was used as an arrowhead by Native Americans, for example, and according to wikipedia, flint is a form of quartz that is described as a form of chert.  Flint can hold a very sharp edge, and would be a useful item for making something like crossbow bolts or even elven arrowheads.  The sort of thing you should be trying to knap in Adventure Mode, definitely.  Giving chert some sort of maxedge property would be a good idea.

Of course, it's kind of weird to apply all the same material properties to chalk as you do to an obsidian arrowhead, but you never know when some odd mechanic somewhere down the road might use it... maybe chalk mechanisms will one day break down faster than granite mechanisms?

[Bohandas]

I support the idea of adding the correct values, especially since Uristocrat has already done all of the real legwork by looking them up.