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Author Topic: Mineral Melting Points (Scavenger Hunt)  (Read 4309 times)

Sweedumz

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Mineral Melting Points (Scavenger Hunt)
« on: September 15, 2009, 09:03:15 pm »

UPDATE:
Looks like this scavenger hunt was already started by the Molten rock mod people, who have done some spectacular work so far. I think it's best to take this discussion over there.

===================================
I ran into the magma safe mechanism problem. What a pain. The only stone with a high enough melting point to resist magma is bauxite. Unfortunately, Bauxite is literally rarer than gold in the game. This has become a real problem for me because I'm playing Goblins, and can't order the stuff in. But it an issue which I know has bitten a lot of people.

There are various suggestions on the modding front, such as adding [ANY_USE] tags for iron, etc. However, I'd like to suggest a better solution which is both reasonable and won't adversely affect gameplay.

The wiki states that magma's temperature is between 1300-1400C. Bauxite has a melting point of about 2000C, so it can survive as a mechanism indefinitely. Iron and Nickel also have high enough melting points, but you can only make mechanisms out of stone!

However, the problem here is not that there are no stones which have high enough melting points. Basically,  if you take a look at the matgloss_stone_mineral.txt file in the raws, you can see that very few stones actually have a given melting point. Having done a little research, I can see why. It's hard to get your hands on mineral melting points, as they're not definite things. Different components have different melting points.

After a bit of googling, I managed to find a list of melting points for the mineral Olivine. Almost every source states this mineral has a high melting point. Wikipedia (uuhh) gives a ranges of between 1200-1900C. The encyclopaedia Britannica website give a range of 1550C to 1300C. A few more sources confirm these ranges. Personally, I'm willing to put down a figure of 1450C for the stone in the game (based largely on the fact that I want to use it for magma safe mechanisms). Since the game needs a single number, I think this is a reasonably fair one to put down in the raw file. However, we should try and discuss this to give the file some veneer of respectability.

====PROPOSAL====

My proposal is this. A group of volunteers take it upon themselves to find as much information about a particular stone in the game as they can, and report back with a list of melting points, etc,  and a range of melting point temperatures, and a recommendation. We take a look at the sources, throw around some guesstimates and all come up with what we hope is a reasonably reflective melting point for the stone in the raw file. For completeness, we should even look at stones with given melting points.

When we're finished, we come up with what we hope will be an accurate and complete matgloss_*.txt files for use in mods or even the main game. Hopefully this process will result in some more usable stones for magma projects, and an improvement for the game/mods in general, but we should try to as accurate as possible regardless of the outcome.

A bit of googleing lead me to, at the very least a range of melting points. With a more work and a lot of hands, I think we can come up with similar ranges and sources in good time.

Here are all the stones listed in the matgloss_stone_gem.txt, matgloss_stone_mineral.txt, matgloss_stone_layer.txt and  matgloss_stone_soil.txt text files in the raws. This is from 40d11 on linux.

From  matgloss_stone_mineral.txt
Spoiler (click to show/hide)

From matgloss_stone_layer.txt
Spoiler (click to show/hide)

From matgloss_stone_soil.txt (Not sure should we bother with these?)
Spoiler (click to show/hide)

From matgloss_stone_gem.txt (This is a long list)
Spoiler (click to show/hide)

I'll start by proposig the first entry in our list, with sources
Quote
==Olivine===
Source1: (Wikipedia) 1200-1900C
Source2: (Encyclopedia Britannica)  1300-1550C

Recommendation: 1450C

Hopefully we can get at least a few more minerals, and hopefully scrutinise the sources enough to come up with the best recoomendations.
« Last Edit: September 16, 2009, 03:05:04 pm by Sweedumz »
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Fossaman

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Re: Mineral Melting Points (Scavenger Hunt)
« Reply #1 on: September 15, 2009, 10:05:17 pm »

I wouldn't bother with the soils. As a rule, all of the organic components (the loam parts) should burn out. Sand and clay might glassify. I'm not sure about that; the melting point for glass is above that of in-game magma, but I don't know if sand that hasn't been glassed already starts going glassy before that point.

Quartz looks like it should change form as it heats up, becoming Tridymite at 870 degrees C and then to Cristobalite at 1470 (and so probably not caused by magma). I don't know if it would maintain its shape as it did so. So I dunno if it would count as magma safe. (I'm not sure if quartzite has similar properties.) This applies to the following gemstones as well: Citrine, Rose Quartz, Amethyst, Chalcedony, Onyx, Jasper, Aventurine, Tigereye, Rock Crystal, Milk Quartz, Smoky Quartz, and Carnelian. So those probably would turn an ugly, smoky white color, possibly with some cracking and damage.

Ruby should be magma-safe, wikipedia gives its melting point at 2044. This google book result seems to confirm in the approximate. Sapphires are virtually identical chemically, so they should also be safe. Diamonds are magma safe (they're found inside ancient magma pipes. That's how they get to the surface).
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winner

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Re: Mineral Melting Points (Scavenger Hunt)
« Reply #2 on: September 15, 2009, 10:52:11 pm »

petrified wood can be made of silica or calcite

calcite melts at 1612 C
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lucusLoC

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Re: Mineral Melting Points (Scavenger Hunt)
« Reply #4 on: September 16, 2009, 12:36:22 am »

wasn't a lot of this done with the molten rocks mod already? or is this to collect references to compliment that?
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Atarlost

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Re: Mineral Melting Points (Scavenger Hunt)
« Reply #5 on: September 16, 2009, 03:18:51 am »

What I'm finding puts glass at 1400-1600 C and Quartzite is going to be the same.  Call it 1500 so it's magma safe, and at least clear glass if not green glass should also be magma safe. 
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BurnedToast

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Re: Mineral Melting Points (Scavenger Hunt)
« Reply #6 on: September 16, 2009, 04:21:38 am »

Glass's melting point is higher then magma. However, it becomes soft and malleable at a much lower temperature (called the glass transition point) which for soda-lime glass is only 573 C, and even pure silica glass is only 1140 C. So it would still be useless as a mechanism (or door, or chair, or....) at magma temperatures, and in fact really should not be considered magma safe at all (as the pressure of the molten rock would likely deform it into a blob).


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Rvlion

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Re: Mineral Melting Points (Scavenger Hunt)
« Reply #7 on: September 16, 2009, 04:30:40 am »

Lets just say that for Glass it depends on which type of glass.
In my personal experience most types of glass starts turning in a liquid pool at >550 C while others (like quartz) can at least survive 900C. I guess some of the more expensive types of glass might survive a heat of >1000 C, but I have not personally witnessed this.
Considering my above personal experiences I would never use green or clear glass as a magma safe material.
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Pilsu

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Re: Mineral Melting Points (Scavenger Hunt)
« Reply #8 on: September 16, 2009, 08:00:04 am »

Magma should really be made hotter seeing we can use it to melt iron

I'm not sure any stone could remain effective as gears and whatnot at such temperatures. How exactly do these gates work? It'd be better if the gates themselves were made more realistic than trying to stretch the handwave further

RandomNumberGenerator

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Re: Mineral Melting Points (Scavenger Hunt)
« Reply #9 on: September 16, 2009, 08:46:17 am »

Magma should really be made hotter seeing we can use it to melt iron

Who said we were melting it? In forges, we only need to get it hot enough to make it malleable. At smelters it only needs to be hot enough to burn out impurities.
Quote
I'm not sure any stone could remain effective as gears and whatnot at such temperatures. How exactly do these gates work? It'd be better if the gates themselves were made more realistic than trying to stretch the handwave further

I always thought it was something like this:

▒▒▒◄███████►▒▒▒
▒▒▒◄███████►▒▒▒
▒▒▒◄███████►▒▒▒
▒▒▒◄███████►▒▒▒
▒▒▒◄███████►▒▒▒
▒▒▒◄███████►▒▒▒
▒▒ ☼                  ☼ ▒▒
▒▒                         ▒▒▒
▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒

The large object in the middle if a floodgate with spiked racks. The ☼ in the middle are gears. When engaged, the gears turn, putting it down. When re-engaged, the gears turn the other direction, lifting it up.
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Granite26

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Re: Mineral Melting Points (Scavenger Hunt)
« Reply #10 on: September 16, 2009, 10:34:45 am »

I'll start by proposig the first entry in our list, with sources
Quote
==Olivine===
Source1: (Wikipedia) 1200-1900C
Source2: (Encyclopedia Britannica)  1300-1550C

Recommendation: 1450C

Hopefully we can get at least a few more minerals, and hopefully scrutinise the sources enough to come up with the best recoomendations.

I think your best option is to maintain a list of references to melting temps in the OP.  I'm pretty sure if everythings laid out, it'll make it in out of shear convenience.

From a gamey perspective, I wouldn't want to see any [Layer] rocks be magma safe, though.

lucusLoC

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Re: Mineral Melting Points (Scavenger Hunt)
« Reply #11 on: September 16, 2009, 11:47:12 am »

i just read the whole thing and a lot of the work has already been done here.

molten rocks mod: http://www.bay12games.com/forum/index.php?topic=32237.30

a snip from that thread:
Quote from: Stakudomer
I've found melting points for a few minerals that aren't in the latest release.

Cassiterite melts at 1125C (12025D). Source.

Sphalerite, according to wikipedia, is Zinc Sulfide and sublimates at 1185C (12133D). I suppose that would actually be a boiling point.

Cinnabar melts at 580C (11044D). Source: Wikipedia article on Mercury Sulfide

Jet appears to be a kind of oil-bearing petrified wood, which is often used as a gemstone. It sometimes contains trace amounts of pyrite, which can cause the jet to spontaneously combust when cut. Maybe it should ignite like coal and graphite?

And speaking of petrified wood, the normal variety seems to be made mostly of quartz. (Melting point: 1650C, 12970D) This leads to the highly amusing scenario of making your magma-safe mechanisms out of former trees.   

Anyway, I'm down to Kimberlite in the raws, and may do some more searching later. I'll let you know if I find anything else.

EDIT: Bismuthinite melts at 760-775C (11368D). Sources are blurbs from a couple of scientific journals that show up in Google, but can't be viewed directly because the sites want outrageous amounts of money to look at them. Search "melting point of bismuthinite" and you'll find them.

Marcasite melts at 450C (10810D). Source

Hornblende: Melts at 1050C (11890D). Source

Microcline is odd because it doesn't go straight from solid to liquid at a particular temperature. A small percentage of it will turn liquid at about 1200C, but it won't completely liquify until it gets to 1440C (just over DF magma temperature). Still, a half-melted mechanism doesn't work any better than a fully-melted one, so I'd say that for our purposes, this stuff isn't magma-safe.

Obsidian melts at 1350C (12430D), so not magma-safe, just in case anyone was wondering. 

Also, I find it funny that Toady put in a comment about Alunite being used to make fire retardent, but neglected to put in its obviously-safe-for-magma melting point.

So this means we're still missing:
Kimberlite
Puddingstone (isn't really a single mineral, but a mixture)
Jet (may ignite)
Cobaltite
Garnierite
Limonite (can't find actual numbers, but sources say melting point is relatively low)

...and several layer rocks that are probably not magma-safe.
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Atarlost

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Re: Mineral Melting Points (Scavenger Hunt)
« Reply #12 on: September 16, 2009, 11:57:59 am »

I'll start by proposig the first entry in our list, with sources
From a gamey perspective, I wouldn't want to see any [Layer] rocks be magma safe, though.
I think that'll be unavoidable.  I'm having trouble finding a number, but a lot of geology discussions indicate that gabbro is pretty much the first thing to solidify as magma cools indicating the highest melting point.  If anything's going to be magma safe it's probably gabbro and gabbro is a layer rock. 
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Evil One

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Re: Mineral Melting Points (Scavenger Hunt)
« Reply #13 on: September 16, 2009, 12:19:47 pm »

I generally find it easier to just make obsidian magma safe and use that.
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lucusLoC

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Re: Mineral Melting Points (Scavenger Hunt)
« Reply #14 on: September 16, 2009, 01:50:51 pm »

assuming gabbro = basalt then: Gabbro Basalt melts at about 984 to 1260

http://www.minsocam.org/MSA/collectors_corner/arc/tempmagmas.htm

also from there: granite at about 1215 to 1260
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