What materials could create a translucent tower?

Question

I’m building a D&D world for a game, and one of the major details I really want to include in this world is the Evil Mage and their tower. The tower is a light blue, 3 stories tall, intricately carved, and translucent/partially transparent. I don’t want to change the boxed text I have for it (reproduced here in case it helps), but I want to know if there is a plausible material useable to build it.

The description I will tell the players is:

As you approach the blue structure, you begin to see more details. The tower raises high into the air, taller than the tiny huts surrounding it. Against the gray landscape, it’s almost an impossibly bright shade of blue, just lighter than [one of the characters who has blue hair]’s hair. When you get closer, you can see faint outlines of creatures moving behind the walls. Light passes through easily, but the intricate carvings of dragons on the walls prevent you from seeing too much detail.

I wanted to know, given that it is a setting where magic is limited (but not impossible, because D&D), whether some substance that lets light through, but is strong enough to make a several story tall building, could exist. Specifically, a good answer here should minimize the amount of magical hand waving; I’m perfectly willing to say “magic carved it”, but “magic made it all” is not plausible in the setting (homebrew world, low magic, modern tech), and I would especially like something plausible in the real world if there is such a thing. The technology level is relatively similar to our own world, probably equivalent to 2010 technology or so.

What material could make such a tower?

Answer 1

Glass and Perspex are possible, however they need structure to make it work. Ice is possible but will melt in summer. If you want to do the entire building out of one material which is transparent blue, may I propose

SLA Resin

It's translucent and can be tinted with dyes, (That manufacturer has clear and transparent green in stock atm, but other colours are possible). Neon blue dyes can be found on ebay.

Strengths vary by manufacturer but 55MPa seems to be a common tensile and compression strength. Concrete varies from 10 MPa for your garden path up to 70MPa for skyscrapers. 55 is right in this ballpark.

It hardens and cures under UV light. So if you don't have a tower-sized 3D printer, you can use the day-night cycle to "print" the tower, just like a 3d SLA printer will do.

Create cross sections of the tower (say every 2mm) in a stencil on a plastic sheet. At night, stretch the stencil out over your site, pour a layer of resin, spread it equally using squeegees, wipe off any excess not in the gaps in the stencil, wait for sunrise, the layer hardens during the day. The next night, lay the next stencil down, and repeat up. It'll take 500 days to build 1m, and you'll need scaffolding, and some temporary structure for supporting the ceilings while they cure, but you should get a nice translucent blue tower at the end.

As it's exposed long term to UV from the sun, it will become less transparent, but never become completely opaque.

Answer 2

it's made of Ice

Ice is cheap, strong, transparent, light blue, and easily carve-and-sculpt-able. Regular craftspeople even without magic can create long-lasting and intricate carvings in ice provided the right temperatures. Furthermore, keeping an ice structure frozen and maintained isn't impossible so long as the climate fits (or a magical cooling spell helps). Furthermore, while it is presumably within a magic-user's domain to cast a "create ice" or "freeze water" spell, building an ice-tower is completely within the capabilities of mundane workers.

Here are some example ice structures.

Answer 3

I would build using standard office building techniques - steel/concrete and glass.

The reason is that there is no reason why you can't build a composite structure. No building is built only out of 1 material.

Some materials are brittle and cannot span as far as steel could, nor could they take much compression load. Buildings today use steel or timber to span long distances, concrete columns to take compression loads and gain height, and glass to allow light in. By separating structure from facade, it allows you to be able to do anything you want with the material on the outside.

So your glass facade (which you can mould to different patterns, carving-like shapes etc.) could be connected to a steel substructure that is thin and recessed (hidden from view).

We build our glass skyscrapers like this today, using a 'curtain wall' system. This is basically an aluminium subframe that the glass connects to, which in turn connects to a steel one, which may then be supported by concrete. The columns that form the main supports for the structure are away from the facade, hidden inside close to the building core.

Le Corbusier, one of the founders of modern architecture, summarised this new form of construction succinctly in one of his drawings: Here you could see that the facade can be any material you want, as there would be no structural function required, allowing for 'glass towers'.

Answer 4

Jade.

https://www.gia.edu/jade-quality-factor

Jade is real. It is translucent. It is strong. Usually it is green but there are bluish varieties. People carve it into all sorts of shapes. I envision every surface being carved into reliefs showing stories of all sorts - like Trajan's Column or some of the Hindu temples.

A single clear piece of jade large enough to make into a tower is definitely the stuff of fantasy but to my surprise I could not find any images! I am positive there was something like this in one of the Conan books. I like the idea that it is said to be the tooth of a dragon.

Answer 5

Glass

Glass is pretty strong, especially if you make the walls two or three feet thick. Perhaps a group of thugs with magic axes or clubs could bash a hole in it. However, they would get hurt from all the glass shrapnel thrown into the air by the pounding.

Magic

I would hope that in a high magical world, somebody would have figured out how to make a spell to make glass as strong as steel or stone, or maybe change it into transparent aluminum.

I'm not sure I'd want to live in a glass building, but each to his own, I say.

Answer 6

Ordinary glass block should work perfectly* well for a mere three stories, and is readily available in a multitude of colors, e.g. https://glassblockwarehouse.com/product-category/shop-by-colors/blue Took under a minute to find that site (one of many) and navigate to the requested color.

*As long as you don't have to deal with earthquake resistant building codes and so on.

Answer 7

Cobalt glass, while not particularly stronger than standard glass (which is remarkably stronger than most people think), does match up to your remarkably blue, transparent building material. It also has the added benefit of being able to partially obscure bright light to some degree, hence its use in flame tests to filter out sulfurous yellows.

It's quite a heat-resistent material, hence its practical use in furnace observation — a property which is especially true as it gets thicker, and consequently more blue — and has been historically quite decorative. But glass as a building material has some distinct disadvantages, particularly how brittle it can be, and that high-quality cobalt glass — most certainly necessary for building larger structures — can be especially difficult to find in large quantities.

Answer 8

Blue Light

https://invention.si.edu/twin-towers-living-light

A four-mile high tower of light can't fail to impress your adventurers. You can see through it and indeed walk through it. The actual tower can be pure white and inside the perimeter of the lights that form a circle around it.

The top of the solid tower could project in such a way as to stop the light going on indefinitely. The dragons could be actual white stone dragons on the walls of the solid tower.

Answer 9

This is close to the look gothic churches were going for: The arches allowed a relativ slender wall construction to fit huge windows. If you change the classical coloured glass panes for clear glass, you are halfway there.

This is 14th century, the Kölner Dom, no magic involved. Note how much of the area is dedicated to windows, and how little to structural supports.

For your tower I would suggest an octagon ground plan of arches to form the walls, with area within the arches as glass windows. As you are in a fantasy setting, you can handwave a few things. The only problem I see is the puny three stories, how is that impressing anyone?

Answer 10

Sapphire.

It's (usually) blue, and it's almost as hard as diamond, so it should be able to support a fair amount of weight.

It's too rare to use as a building material in our world, but in your world, it can be as common as you want. Or, since it's basically aluminum oxide with a little bit of other metal, it could be manufactured in large quantities by some quasi-magical process.

Because of its hardness, you'd probably have to use diamond tools to carve it.

Answer 11

Consider the purpose of the tower - why is it blue and translucent? If it's a magic flex, then I'd push the magic component as far as possible strictly because it's unique, but you don't have to say it was simply conjured. Combinations of magic and science described above work great, but you can also grow a synthetic crystal (aided by magic to account for size) and carve it. If you want the flex to be more "OMG this guy is frickin' loaded!" go with cut quartz, cordierite, or apatite blocks, built and carved by expert masons to be nearly seamless. You will still need some magic to explain the color.

Your major limiting factor is actually the light passing through easily. No natural material that can be carved into recognizable shapes and also has the strength to be used as a functional wall for a 3 story building will allow that much light through it.

You COULD just go with glass if you can pass off the optics (if there are no distortions it may as well be 100% magic). At 3 feet thick it would still allow a measurable amount of light through, and you could arguably use 1.5 to 2 feet for functional support in concert with a strong metal framework - being mindful of the fact that crystalline structures are NOT very useful when it comes to load-bearing, which is why you find transparent material, even those mentioned as examples above, predominantly used as curtain walls rather than supportive material.

Since in this case the transparency is only useful as an aesthetic, I'd go with a magic flex.

Answer 12

I see four categories:

1. Without any magic.
2. Magically created, but functional without.
3. Magically supported or suspended (e.g. ice + cooling)
4. Illusions.

That said here are my solutions:

1. Multilayered glas with rhomboid steel supports: In a glas stack of 15-20 cm you can easily hide steel frames that are 10cm deep and 3cm wide, as long as one of the outside layers is frosted. The flat angles provoke a total reflection and thus make it difficult to see the steel. You'd have to look at the wall under a rather flat angle, but then soon the reflection of the wall make things difficult to see. Glass is much tougher than people assume, but the toughness is kind-of concentrated in the surface. High-strength glass therefore often is laminated.
2. Fused crushed glas with thin steel supports: If you crush glas and fuse it, you get a translucent material that is not completely clear and has a very 'frozen-lake'-like icey look to it. The same rules on hiding steel frames apply, except that it is much easier to hide, and thus could also be round steel, etc. Depending on crumb-size and amount of sintering, you can also gradually vary the clearness, allowing for the wall to become a window in some places. Bonus on stability: Since the wall allready consists of sintered broken glass, on impact the original shards will lead the cracks, so only small shards will spray off. Also it is a bit more flexible, which in turn will make it much harder to get in deep. (Think of it as "ablative shock absorption"). The look might be similar to this (especially the second and the last images).
3. Simple glass brick: Building bricks for glass-sections in buildings were common in the 30s to 60s for staircase-walls. Usually hollow and not load-bearing, but they can be filled with crushed glass (half-bearing), or be massive (load bearing).
4. colophony/rosin and polymers: Many modern polymers are translucent or transparent. If you have access to them, you can build the tower from them, with glas dust as filler (fiberglass would also be an option). Otherwhise you can use plant-based substances like plum-sap residue (a clear rubber), some kind of cauchuck or latex, or colophony/rosin (boiled plant resin, goes from white over yellow, red to brown).
5. Transparent stone: If you can get transparent stones like quarz or similar, that's a way, of course, but asuming you've got limestone or sand stone, your mage could just glassify parts of it, passing it through like fibers. The result would be simmilar to transparent concrete, even with rather high transparency, but you can of course design it to be coarser or make it look like crystal-layers.
6. Conjured organic matter: A pair of semi-transparent substance are Fluorapatite and Hydroxylapatite, which range from white over gray, greenish, yellowish to brown (no blue, sorry). They build the backbone of all hard substances in your body (spare for horn, which is not really hard). The hard part of your teeth (enamel) is indeed made out of them by 96%. Your wizzard could conjure up a tower of tooth enamel, which you could shape acordingly if you want to. If your wizzard is a necromancer or something weird, this may fit perfectly. Otherwhise, it might be interesting to use horn, which indeed is also transparent and can go from almost clear whitish to slightly greanish over all states of yellow, red and brown down to black. Horn is made from creatin and is usually not that clear, but hey, your mage might conjure up rather clear horn. You can see examples of natural clear horn (2.5mm thick) here, here, here or here. It would surely make for a sick building that could also work for a friendly/nature-loving conjurer. (Horn substance is stronger than most woods, so you could easily build the tower from that.)
7. Cooled Ice: Casting an freezing spell would allow to maintain an ice building. Adding plant fibers makes it less clear, but tougher to destroy. (see Pycrete, which melts much slower than ice and can reach strengths near to concrete)
8. Illusion: A transparancy spell, some kind of modified invisibility spell or some kind of projection spell onto normal building materials would do it. This spell would falter once the caster is dead, or the taumic source is depleted.

Personally I'd go with either the crushed-sintered-glass or the horn aproach and colorize that. I guess that looking like this transparent stone would also be plausible style, eventhough it wouldn#t be bright blue (on its own at least, but it could be painted). If you don't care about clearness, so diffuse shadows are enough, and can take a cooling charm, you could use pycrete. Keep in mind it took three hot summers to melt a Pycrete prototype ship the canadians had built.

Answer 13

There is a way to make Aluminum clear as Glas. It is difficult but wiht magic... integrate some particels for the blue look and you have a very solid blue Glas, that is not Glas.

"Aluminium oxynitride or ALON is a ceramic composed of aluminium, oxygen and nitrogen. It is marketed under the name ALON by Surmet Corporation.[3] ALON is optically transparent (≥80%) in the near-ultraviolet, visible and midwave-infrared regions of the electromagnetic spectrum. It is four times harder than fused silica glass, 85% as hard as sapphire, and nearly 15% harder than magnesium aluminate spinel. Since it has a cubic spinel structure, it can be fabricated to transparent windows, plates, domes, rods, tubes and other forms using conventional ceramic powder processing techniques. ALON is the hardest polycrystalline transparent ceramic available commercially.[2] Its combination of optical and mechanical properties makes this material a leading candidate for lightweight high-performance transparent armor applications such as bulletproof and blast-resistant windows and for many military infrared optoelectronics.[4] ALON-based armor has been shown to stop multiple armor-piercing projectiles of up to .50 BMG cal.[5] It is commercially available in sizes as large as 18 by 35 inches (460 mm × 890 mm) monolithic windows.[6] "

https://en.wikipedia.org/wiki/Aluminium_oxynitride

Answer 14

There are translucent concrete projects in the works, with the Japanese being the leaders in this research, I believe. Similarly, some Japanese are the leaders in aquarium and deep-sea diving glass-incredibly thick yet perfectly translucent glass. Some aquarium glass is many meters thick. wall of such glass could easily stand for some time under immense (self)load.