This support my opinion.
The next question would be if the unnatural shape has to take context in opinion. To use the first example from our CrAq section is a good example: It creates an icicle, free-floating, at touch range. Is this natural? It totally is a shape that could be formed, naturally without human intervention... except that it would have to be hanging from a thing, rather than just in someone's hand. Or sticking out at a 45 degree angle from the ground, or on a wall.
Dagger of Ice (HoH: S pg 35) uses the Base 3 "Create ice in a natural shape, such as a floe or icicle" guideline to create an icicle in mid air and fling it at a target. The spell you're discussing* sounds similar, so is probably reasonable in that regard?
I don't think I've got access to the spell list to see it, but I'm assuming it's not Dagger of Ice itself you're talking about even though it's the first item in the HoH:S CrAq section as that's Voice range and canonical.
@raccoonmask
Just saying sorry ahead of time for blowing up your two CrAu spells. The Overwhelming Gloom And Damp only needs Size to be as large as described, while Calling the Spite of Vulcan has the potential of allowing 100 pace diameter +10 damage CrAu(Ig) fireballs with no Size if allowed without changes.
I look forward to checking it when I get Auram. Trying to finish up Aquam.
Here to annoyingly quibble about rules again!
Since we have a lot of 'transform water into x' spells in MuAq, I figured I should bring this up here.
While I mostly agree with Troy's statements that transforming Water to Wine causes the liquid to shrink in size, I found myself looking at Earth that Breaks No More (MuTe 20), which turns earth to stone with no mentioned size change [and I checked errata, changes the ] - we should assume the spell has some weird nonstandard effect, or am I missing somethihng?
I also had a weird mental image of transforming Wine to Water, which obviously causes nearby barrels to explode into a hundred times their volume, drowning people involved.
While I’m not active with vetting spells for this project a solution for the shrinkage due to base individuals I’ve seen proposed was either limit the amount the spell can change to the smaller volume or add one or more size mags to account for the change in volume the spell can handle on the smaller base individual end of things. I don’t actually think the volume of the liquid should change but the spell should fail if it will be too much volume to be a valid target during the spell’s ongoing effect. Beer is not “denser water” and the general effect for most forms of going outside the limits of a valid target due to insufficient spell size is just that the spell doesn’t work. If I want to change some water into a highly corrosive or poisonous liquid all I should need is that thimbleful of liquid I would have at the end, I’d rather not need a whole lake or pond to get that thimbleful and if you do need that whole pond then why does Aquam work so differently than all the other forms when it come to physical muto changes?
IIRC it was @callen who proposed something along these lines and if it was maybe he could explain it better.
EDIT: On another note, thank you all for doing this work. I greatly appreciate it.
I don't really have anything to add, but am super grateful this project is continuing. 
I think, annoyingly for me, Muto Terram has an example of turning a cubic pace of stone into a small gemstone in the guideline sidebar, but then has Earth that Breaks No More.
@raccoonmask : My understanding is that Muto can make different types of change. One is when you change the Substance other is when you change Quality. (A&A p. 22.)
When you change Substance you can make dirt as hard as stone without actually changing it into stone. It is dirt, but with great hardness.
When you change Quality you can change dirt into stone, or water into gem. In this case you will experience quasi-real change and the matter will change in its amount.
That's why the Core Rulebook says separately in the MuTe GL at Level 3 the following things:
Change dirt so that it is slightly unnatural (requisites may be required).
Change dirt into a liquid or gas (with requisites).
Change dirt to stone, or vice versa.
There is a published spell for changing water to wine with no unnatural which shrinks a large bucket of water to a cup of wine.
As RP pointed out, you can mostly get around the growing/shrinking by using some degree of unnatural change. To figure out the degree of unnatural needed you compare how many steps the Base Individual would change. Dirt as hard as stone is +1 slightly unnatural. To make it as hard as steel would be +2 very unnatural. Water that looks and taste like apple juice would be +1 slightly unnatural, while water which looks and taste like wine (along with getting you drunk) would be +2 very unnatural. The reverses could also be applied.
Spells that change between different sized Base Individuals without some degree of unnatural are a pain if what it is changed into has a larger Base Individual. There are no spells in the document that do this for Aquam, though there might be for later Forms. How we would handle it doesn't need to be decided unless it comes up.
Thanks for the great discussion. I think I just have to assume Earth that Breaks No More is a weird case.
I gave a pass back over the remaining Animal spells, added comments to the few that didn't have any and added my vote to others. There are a couple that @Red-Shadow-Claws could move to the final document, a couple for deletion and a couple that could be moved to the holding area for later. Marked as resolved several comment threads where we reached a consensus and the change was made to the spell to cut down on the number of comments (only when all issues in the thread were resolved).
If the less active reviewers could take a little time to go through the Animal section and add their vote for some of the stuck spells it would help clear them out.
Realized I was working through too fast (into Auram) and that was causing a large backlog of unresolved spells. Will hold off for awhile to avoid excessive comment bloat.
I think it would be good to have separate places to debate the different rules decisions for large numbers of spells I'm looking at you, everything involving ice.
Also, I've stopped doing most spelling and grammar fixes, because it adds more comments. We can do that at the end when we all agree on what spells work or not.
Per a discussion between reviewers, requesting that from now on the title of spells be only used for a "thumbs up or thumbs down". Notes on the spell should be placed on some part of the body of a spell. This will greatly speed up future review by placing the votes for or against in a consistent and easy to access location.
Since I covered further in the document than others have,have been going through my comments and moving them from the title to somewhere in the body if no one else has commented yet.
This is the rule "The amount of material you can change is limited by the guidelines for each end." the stone to gemstone is then an example. I don't think shrinking is required as long as the size magnitudes are accounted for. In this instance, +1 size is enough to account for the volume of the stone after the transformation.
Sorry for the slight hiatus in commenting. I'm back and will try to catch up.
@temprobe : Earth that Breaks No More (MuTe 20) is lazy written. You can change only the hardness of the dirt, so it stays as dirt, but hard as stone. That way there is no csange in the amount of material. It is detailed in A&A p. 22.
With the original text - but maybe the intent was not to change the dirt into real stone, but have really hard terrain to walk on - there will be size change.
You should never take the title of a spell like its a description. The description is pretty clear that dirt becomes stone, not that dirt is made tougher. I have no idea why you're refering to A&A 22, but I'm sure such a reference is not needed to explain a base book spell.
As far as Muto individual-type changes, the question needed to answer is, RAW/RAI, we know a cubic pace of stone can turn into a cubic foot of metal... but can we also turn a cubic foot of stone into a cubic foot of metal?
I agree that the issue with Earth that Breaks No More is a bit sloppy.
I believe so. If volume conservation was impossible, beyond Earth that Breaks No More, The Crystal Dart would require a huge boulder to form the small gemstone which is launched and Armatura Vitrea would make the armor expand to become a room.