You remember Star Trek IV when Scotty makes a trade with a manufacturing scientist. He trades the atomic matrix of transparent aluminum for sufficient Plexiglas to fabricate a holding tank for humpback whales "George" and "Gracie". Of course, time travel was involved.
Wiki tells that aluminum atoms typically arrange in a face-centered cubit structure. Also, reputedly Napoleon III gave a banquet where the most honored guests had utensils of aluminum because it was more precious than gold. Even when the Washington monument was constructed in 1848, aluminum cost the same as silver.
Transparent Aluminum Is 'New State of Matter' tells that Oxford University scientists have used a laser to knock out an electron from every aluminum atom in a sample to create a new material transparent to extreme ultraviolet radiation. Well, for a short time - 40 femtoseconds, anyway. The laser produces short pulses of soft x-ray light with ludicrous energy.
Although the material is only transparent for a short time while under intense optical illumination, researchers claim it represents a new state of matter. The European alchemists where hoping for a permanent transformation, but this is like the transmutation of an element.
If you are indeed shopping for something with permanent transparency, you might consider aluminum oxynitride. As described in New Aluminum Windows Stop .50 Caliber Bullet, a high-priced compound with an inner layer of actual glass is available as a new form of glass armor.