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[Uristocrat]

Okay, I have updated soil density data in the thread now based on that great new source I found.  I'll have to upload these new RAWs I'm working on eventually, but I want to get all the wood data in there first.

I'm going with bulk density for soils due to the fact that they're basically tiny rock particles with a lot of air in between them.  So specific gravity would put them on par with ordinary stone and wouldn't give them credit for being largely air.

If anyone was wondering, from largest to smallest grain size, you have:  gravel, sand, silt, then clay.  Loam is a roughly-equal mix of sand, silt & clay.  There's something called a texture triangle which is where all those weird soil names came from (loamy sand, sandy loam, etc.), because soils are classified based on what % of different grain sizes they have.

Yeah, that book I linked to called the "Petrology of Sedimentary Rocks" had a lot of crazy stuff in it about this, but that online calculator was a lot more useful.

[Uristocrat]

We now have a new version of the RAWs.  This adds more wood densities as well as state colors.  A lot of those were already in there, but I added quite a few, too.  I also added a lot of notes to my raws showing exactly where I sourced the data.

There's a ton of other structural data for wood in there, too, which I don't know how to make use of yet.  Help there would be appreciated.

Downloads:
V1 RAWs (OLD)
V2 RAWs (NEW)

[NW_Kohaku]

Okay, I have updated soil density data in the thread now based on that great new source I found.  I'll have to upload these new RAWs I'm working on eventually, but I want to get all the wood data in there first.

I'm going with bulk density for soils due to the fact that they're basically tiny rock particles with a lot of air in between them.  So specific gravity would put them on par with ordinary stone and wouldn't give them credit for being largely air.

If anyone was wondering, from largest to smallest grain size, you have:  gravel, sand, silt, then clay.  Loam is a roughly-equal mix of sand, silt & clay.  There's something called a texture triangle which is where all those weird soil names came from (loamy sand, sandy loam, etc.), because soils are classified based on what % of different grain sizes they have.

Yeah, that book I linked to called the "Petrology of Sedimentary Rocks" had a lot of crazy stuff in it about this, but that online calculator was a lot more useful.

Yes, I'm very well aware of colloid grain size from the Improved Farming thread and talk about ceramics and glass in other threads.

The really big problem is that colloid grain size "sand" refers only to the size of the mineral, not its actual chemical composition.  Black sand, for example, is typically formed when obsidian or basalt, or other very dark igneous rocks are ground down.

This is a problem because the sort of "sand" we want for glass is high in silicon, which is the primary component of that glass, and "sand" as a colloid grain size tells you nothing about what elements or compounds make up that sand.  Black sand is black because it's filled with iron and manganese, which are elements you don't want in glass-making sand.

Likewise, "clay" just refers to a very fine type of soil, but has nothing to do with the chemical composition of what you want in the body of your ceramics.  You actually want mostly aluminum and silicon (ceramics and glass are not terribly different from one another on a basic level, and porcelain is semi-transparent because it is roughly half "glass" in composition), and simply having finely eroded soil is no guarantee of its chemical composition.

The problem is that DF has no respect for the different ways in which the words "sand" and "clay" can be used. 

[Uristocrat]

It's funny, because black (iron) sands can be a source of iron.  Poor quality to be sure, but iron none the less.  Though we already have goblinite for our iron needs

Seems like almost no one understands the material definition tokens.  In spite of having tons of data on wood right now, I have very little idea how to feed it to DF.

[NW_Kohaku]

I'm pretty sure nobody understands materials properites because Toady hasn't told anyone, and he occasionally changes it.

As people have pointed out, they aren't really even all the right metrics for modeling how well objects hold up to stress.

People just have to mod various things and test out every iteration of the materials properties to see what gives an advantage, and what doesn't.

In fact, I'm pretty sure Toady's just "eyeballing" the results, and just changing the formula to make things "look right" for the given values he has, already.

[Uristocrat]

I'm pretty sure nobody understands materials properites because Toady hasn't told anyone, and he occasionally changes it.

As people have pointed out, they aren't really even all the right metrics for modeling how well objects hold up to stress.

People just have to mod various things and test out every iteration of the materials properties to see what gives an advantage, and what doesn't.

In fact, I'm pretty sure Toady's just "eyeballing" the results, and just changing the formula to make things "look right" for the given values he has, already.

I know there are a bunch of things with suspicious default values.  We now have tons of data on wood, though, if anyone knows how to make use of it.

[Shinziril]

Quick look at the eight ungrouped gemstones:

Tiger Iron is basically bands of tiger's eye, hematite, and red jasper, according to the Wikipedia article.  Tiger eye and jasper are both quartz-based, so tiger iron could probably go in the "quartz" group. 

Schorl is apparently tourmaline, so that can go in the Tourmaline group.

Variscite is hydrated aluminum phosphate, which doesn't fit into any of the groups you currently have.  It could be grouped under "phosphate minerals", but it would be the only member currently in DF.  Turquoise is about the only other commonly known phosphate mineral (of course, variscite itself isn't exactly commonly known). 

Chrysocolla is hydrated copper silicate, which doesn't go in any obvious group (it's not really a quartz mineral, although it's associated with quartz and copper ores for obvious reasons). 

Pyrite is iron sulfide, which again doesn't go in any obvious group. 

Peridot is simply gem-quality olivine, which is a (magnesium/iron) silicate.  No obvious grouping here. 

Tanzanite is calcium aluminum hydroxy silicate (yeesh), which again doesn't fit into any of the other groups. 

Kunzite is lithium aluminum inosilicate, in a class referred to as "pyroxenes".  Jadeite is also in this group, and is apparently one of the two minerals recognized as "jade" (the other is nephrite), but you might want to keep the jades group exclusive to actual jade minerals. 


I might work on a possible framework for material values.  Metals are really easiest to characterize, particularly because they tend to be isotropic (uniform characteristics in all directions) and similar in tension and compression.  Ceramics and wood are harder, particularly wood, since wood is basically a naturally-occurring composite material and is thus highly non-uniform.  At least wood's properties tend to be definable as three sets of characteristics at right angles to each other (orthotropic behavior). 

[Uristocrat]

I might work on a possible framework for material values.  Metals are really easiest to characterize, particularly because they tend to be isotropic (uniform characteristics in all directions) and similar in tension and compression.  Ceramics and wood are harder, particularly wood, since wood is basically a naturally-occurring composite material and is thus highly non-uniform.  At least wood's properties tend to be definable as three sets of characteristics at right angles to each other (orthotropic behavior).

That would be fascinating, really.  I didn't link it all up, but I have a LOT of data for most types of wood (there are now wood densities in the raws, which link to sources with a LOT more data, including MOE, MOR, WML, etc. for most woods).  The hardest wood to find information on, sadly, is saguaro rib wood.

The weird thing is that I actually live in an area where that's available, but it's legally protected.  You either have to hike to a BLM-owned area and harvest a small bit of a dead one (which you're allowed to do once per year according to information I found, provided it's for "personal use"), or you can remove dead wood from private property if you have permission and turn in some paperwork (along with $8 or so), which apparently requires a month for approval and you have to write down all kinds of information on exactly which parcel of land you got it from.  Yeesh.  At least your permission lasts for one year, once granted.

Oh, people also sell it online, but nobody wants to give out a price and one of the two sellers I could find only sells it in 50-rib bundles (4 minimum).  There's a nice dead one by the first Casa Grande exit on I-10 E, but I have no idea who owns that land.

[Uristocrat]

Recent Updates:  I added a few more notes on my sources, as well as a link to MatWeb, which BishopX passed along to me.

I know that my sources aren't always easy to find.  The sources for wood density and color are the URLs given in the V2 RAWs.  Yes, that means that I mostly used text descriptions to figure out the color.  If any of them seem off, please let me know.

The gem density information came from only a few sites, which are mentioned in the gem section, possibly with the inclusion of some data from Wolfram Alpha.  The color information was from me doing a bunch of Google image searches, and double-checking the linked pages to ensure that the pictures were of what they were supposed to be.  And I'm still not completely sure what to do with some things like bloodstone, which is predominately dark green, but which has red bands.  As I recall, I defaulted to not changing things, so I think I left it as a "red" gemstone.

The stone density information is linked from the first post and should be easy to find.  The information on where Tanzanite should occur is also linked.  Given that peridot is gem-quality olivine, I wonder if it shouldn't occur in olivine clusters?  Wikipedia gives this information:

Translucent olivine is sometimes used as a gemstone called peridot, the French word for olivine. It is also called chrysolite, from the Greek words for gold and stone. Some of the finest gem-quality olivine has been obtained from a body of mantle rocks on Zabargad island in the Red Sea.

Olivine/peridot occurs in both mafic and ultramafic igneous rocks and as a primary mineral in certain metamorphic rocks. Mg-rich olivine crystallizes from magma that is rich in magnesium and low in silica. That magma crystallizes to mafic rocks such as gabbro and basalt. Ultramafic rocks such as peridotite and dunite can be residues left after extraction of magmas, and typically they are more enriched in olivine after extraction of partial melts. Olivine and high pressure structural variants constitute over 50% of the Earth's upper mantle, and olivine is one of the Earth's most common minerals by volume. The metamorphism of impure dolomite or other sedimentary rocks with high magnesium and low silica content also produces Mg-rich olivine, or forsterite.

[Uristocrat]

I was rather unhappy with the educated guesstimate of 300 that I had to put in for Saguaro wood.  It's reportedly "very light" and there's research out there about how strong it is and whatnot, but reporting the ratio of Young's modulus to the density doesn't help me very much when I want the density itself.

So I'm about to resort to the direct method.  That is to say, I found a kindly local craftsman who makes art out of Saguaro wood who is willing to send me a few scraps of it.  Right now, we're waiting on shipping.  And I have my micrometer and digital scale at the ready so that I can determine the density.

I'll try to post my research back here once I have my samples.

[Doodle]

A framework for trends of natural composition and the material values thereof strikes me as something that could be extremely important in the future if we ever start getting more than the rather homogenous walls to mine out we've got now.

I'm curious if you know more about the exact way the Forest Service got those measurements. I don't doubt that they do a good job in selecting a sample population. It's a little anal on my part probably but I imagine that quite a few species of trees would be different enough to be worth noting if they were grown in a drastically different soil or climate.

I also imagine the world generator will occasionally fling some species into environments their real life counterparts have never set root in, so I might be asking for data that technically doesn't exist beyond the hypothetical.

In that train of thought, since wood can dry out, rot, burn, etc, if those changes are ever respected values for the results could eventually be useful as well.

[NW_Kohaku]

I was rather unhappy with the educated guesstimate of 300 that I had to put in for Saguaro wood.  It's reportedly "very light" and there's research out there about how strong it is and whatnot, but reporting the ratio of Young's modulus to the density doesn't help me very much when I want the density itself.

So I'm about to resort to the direct method.  That is to say, I found a kindly local craftsman who makes art out of Saguaro wood who is willing to send me a few scraps of it.  Right now, we're waiting on shipping.  And I have my micrometer and digital scale at the ready so that I can determine the density.

I'll try to post my research back here once I have my samples.

I'm just posting to say you are truly a credit to dwarven !!SCIENCE!!

[Uristocrat]

I'm curious if you know more about the exact way the Forest Service got those measurements. I don't doubt that they do a good job in selecting a sample population. It's a little anal on my part probably but I imagine that quite a few species of trees would be different enough to be worth noting if they were grown in a drastically different soil or climate.

I have no clue, sadly.  However, the next step, after I finish my measurements, will be to contact them and offer them the opportunity to study the samples I have obtained.

I have no idea how that will go, frankly, because I don't want to say anything until I have actual pieces of wood in my hands.  But I'm hoping that maybe, just maybe, they'll take it to their labs and do some testing and we'll end up with a full data table, like they have for many other wood types.

If anyone has suggestions or knows someone who actually works there, please let me know.

[Doodle]

That's really pretty awesome.

Come to think of it, are there even any instances in the real world where cactus wood is used as a building material? Lumber and carpentry and the like could not even remotely be called my forte.

[NW_Kohaku]

That's really pretty awesome.

Come to think of it, are there even any instances in the real world where cactus wood is used as a building material? Lumber and carpentry and the like could not even remotely be called my forte.

I seriously doubt it. 

Saguaros just grow too slowly and too sparsely to be a major construction material.

Real-life indigenous peoples who lived in those regions made their houses out of clay or mudbrick, or carved their homes out of the faces of cliffs.  Wood may be easier to work with when it's plentiful, but you pretty much never run out of soil and stone.