Jewels have been mentioned elsewhere as a main technology. They're very similar to the types explored in oceano/ikthulu/TDoN, just modified for different uses.
Jewels have dull uncharged forms and lightly gleaming high-sat charged forms, with a lot of gradation in between. Charging them involves exposing them to whatever charges them, where they'll collect it.
Jewels must be powered to use them. This is done by exposing them to Sunstones or wires that carry Sunstone energy. These aren't circuits; they transfer energy one-way.
Sunstones
Sunstones form the energy requirements of the world. They're charged from sunlight and so long as they're in the presence of sunlight they'll continue charging to their capacity. Usefully the amount of charge is viewable as charging creates bands of orange/yellow/gold separated by off-white bands. A fully charged Sunstone will be have stripes of off-white and gold.
Sunstones that are touching crystals will power them fully, while touching silver will give off smaller amounts of energy, based on the size of the silver filament. Sunstone output can be carefully controlled with the size of the silver/gold filament or wire.
Sunstones that touch gold will make the gold glow and put out something equivalent to sunlight, draining the sunstone slowly. Power can be routed from silver to gold.
Sunstones can also charge each other -- the higher power one will transfer energy via silver or sunstone-touching until the two are equalized. This is particularly useful for lighting areas continuously -- one large sunstone can be replaced that powers all the smaller ones attached to gold.
The currency of the game are sunstones, either dead pebbles of them (which charged ones can be traded for with a fixed exchange rate) or regular ones where the energy amounts are clearly marked on the sunstone itself.
Since they maintain their power if they aren't touching a crystal or precious metals, they're very useful as a general currency. And throwing a bunch of sunstones in a barrel isn't a big deal since no power is actually lost; the power will just get distributed evenly between them.
If you want to hoard money, it makes more sense to get a big sunstone, some platinum wire and then stick the sunstones on it. Platinum always transfers energy the opposite way to silver so so long as the big sunstone has more power than anything you attach it'll continue to fill, with bigger wires transferring it much quicker.
Solar Churches are ubiquitous and offer a fixed exchange rate between uncharged sunstone and charged ones, so you go there with your dead sunstones to get more energy -- you lose dead sunstones in the process but they're a currency so you'll get more later at whatever your job is.
Meanwhile, charged sunstones that you've used up are still valuable as a currency.
Jade has been outlined elsewhere, but it basically allows for permanent and very condensed storage of information. It actually transfers information to and from jade in written black-and-white form, so you can just write something by hand and distribute it very easily. Books are therefore handwritten rather than printed, and drawings or charts/etc are very common as well.
Amethysts
Amethyst technology borrows from TDoN -- it basically allows remote transmission of energy, allowing for instant communication across big distances or even the transfer of Windows for transmission of physical objects.
Amethysts are charged and paired by attaching two together and powering both. They turn from a dull purple to a gleaming high-sat purple when charged.
Once paired, putting energy into one will output the same energy out the other, assuming there's something attached to it. The distance between the two doesn't matter.
This isn't a useful energy transfer system because Amethysts will lose their charge over time -- transferring sunstones or having dedicated wiring is still better.
Amethysts can however be charged by other Amethysts via silver or platinum.
I'm not sure yet how communication works exactly, will need to brainstorm that some more.
Onyx
Onyx creates pockets of Void separate from but attached to existing space.
Onyx is always found in its charged form and generally clustered together because it gains charge by eating the space around it. When powered, it will create a two-way Portal to that space, and unpowering it will close the connection. The Onyx will however exist in both spaces simultaneously so getting trapped in one of those spaces is unlikely.
Powering an Onyx while it's attached to Amethyst will transfer the space to the other side -- the onyx will still exist on the starting side, but a portal will open up via the amethyst on the receiving side.
Onyx is unique in that there's no way of reducing its charge or it losing potency over time. It's possible that it doesn't even *have* an uncharged form.
The size of the Onyx determines the size of the space that's created.
While it theoretically creates Void, when Onyx forms it naturally pulls air and rock out of wherever it was made so the space there isn't free from air or anything.
Onyx is typically used for Courier services as well since goods can be stashed in one of its spaces and then the Onyx can be moved around and reactivated at the destination. The downside is that it does require kind of a lot of power to open a portal and this scales by the size of the space so it isnt great as a general storage mechanism -- Guilds really need to open portals at their bases, load goods in, close the portal and then receiving guilds would then power the Onyx at the destination to retrieve the goods.
It's definitely useful for instantaneous transport of goods or people though. The energy costs are high so these kinds of connections will typically be operated by the Solar Priests who have a vast wealth of energy and a lot of incentive to keep this infrastructure solid.
They won't do this everywhere though -- maintaining the connections between major hubs makes the most sense and goods/people can be transported around an area through slower means such as Skeletal transport or boats.
Onyx worlds are not free from Scrying. Since they're the main way of transporting goods around, expansive Guilds can't effectively make moves without coming under scrutiny by the prying eyes of rival Guilds.
Your Onyx world is the singular exception because of your Wraith magic. You're completely undetectable while in Wraith form and your Onyx world is perpetually wraithed. This is a very ancient Lunar technology that has otherwise been lost to time.
