[Magic\Thaumatology] Gemstones For Powerstones By College

[scc]

So I've floated this idea in the past, but I've finally worked things out, so I'm providing details. Under this proposed rule to make an actual Powerstone you can't just use any old item, if you do you end up with a non-reusable Manastone, rather you must use a jeweled item, and not just any old jewels, the jewel or jewels in the item determine what Colleges the Powerstone can power, as detailed below:

Air: Iolite
Animal: Cat’s Eye
Body Control: Bloodstone
Communication and Empathy: Turquoise
Earth: Topaz
Enchantment: Moonstone
Fire: Ruby
Food: Amber
Gate: Garnet
Healing: Diamond
Illusion and Creation: Tourmaline
Knowledge: Jade
Light and Darkness: Beryl
Making and Breaking: Alexandrite
Meta: Opal
Mind Control: Emerald
Movement: Calcite
Necromancy: Onyx
Plant: Peridot
Protection and Warning: Sard
Sound: Lapis Lazuli
Technology: Amethyst
Water: Aquamarine
Weather: Sapphire

[Anders]

Very nice. How did you come up with this list? Was it just made up or did you research modern occult practices?

[AlexanderHowl]

Unfortunately, that arrangement would result in a violation of the price formula of Powerstones (which require gem quality semi-precious stones for the lower energy cost). For example, gem quality diamonds, emeralds, rubies, and sapphires (at least natural ones), would easily cost 50x-100× as much as gem quality topaz or moonstone.

[William]

Just means the more expensive ones don't need to be very big and vice versa.

[AlexanderHowl]

The default is one carat=one energy. To get a $40 gemstone for a one energy powerstone, you would need a .02 carat emerald (a 4 milligram stone). I do not think that TL 4- civilization can shape stones that small.

[Plane]

There should probably be some materials out there which could create stones for multiple colleges, or some ultra-good thing which can create the all-college powerstone that everyone desires. Is there anything appropriate which doesn't fall under these?

What about biologicals like pearl/ivory?

[William]

Emerald has a density of about 2.7 g/cm^3. A 4mg gemstone would be a cube a little over a millimeter on a side, which is fine work but not impossible I would think.

At worst, since a stone that small would not need to necessarily be particularly well cut, an emerald could simply be ground until a large number of stones of roughly appropriate size were created for enchanting stock.

[Stormcrow]

Originally Posted by AlexanderHowl

The default is one carat=one energy.

The word carat does not appear in GURPS Magic or GURPS Thaumatology, according to PDF searches. Where does this default come from? Is this a 3rd edition rule?

[Culture20]

Originally Posted by Stormcrow

The word carat does not appear in GURPS Magic or GURPS Thaumatology, according to PDF searches. Where does this default come from? Is this a 3rd edition rule?

Yes, and one I just recently fell afoul of when determining the carat weight of some gems my PCs found where the value was previously determined. Turns out the carats didn't matter after I wasted time with a spreadsheet.
It's sooo easy to have 3e magic bleed into 4e given how close they are in most things.

[Hyrneson]

This is a handy page with tables I keep around.

https://www.gemsociety.org/article/s...m-sizes-chart/

This one too;

https://www.stonemangems.com/index.p...ormation_id=66