Elven Glass is the fantastical building material from which the crystal treehouses of River Tower were constructed by ancient Elves. It has the appearance of leaded crystal but the strength of steel, and can be used for a wide variety of structural elements, from thick buttresses to thin strands of wire that can be braided together into cables strong enough to take the weight of a bridge. It is not blown like glass, nor forged or cast like metals, but grown organically by Elven engineers, who persuade the glass to act like a living plant, reaching for a source of sunlight. In this way the glass is ‘trained’ and ‘pruned’ into the form desired by the architect, a process requiring decades or centuries for large structures. No magic is involved, just the touch of a trained elf. Today, all such engineers are found in River Tower, though in former times some dwelt in Dortin. For example, a pirate captain of the Northern War is credited with growing the first Elven glass in the city.
River Tower actually took its name from the great numbers of such structures found there, a skyline visible from many miles off. The use of Elven glass is much more modest in Treetown, just a few walkways in the canopy and decorative elements on the oldest treehouses.
Elven glass is also used for smaller items such as jars and vases, though since it is ‘alive’ it tends to deform noticeably over time when used in such small amounts. An elf would say this is because the glass has no ‘purpose’. Nonetheless, a vessel made of Elven glass is indestructible except by magic, and ‘heals’ itself of all damage within one week. Obviously, with no one producing the glass in Dortin, such items are bound to be rare and expensive. Add 500 GP per pound to the normal price of the base item.