Gustave Falconnier's Blown Glass Bricks

Falconnier's bricks were used by important period architects such as Hector Guimard, Auguste Perret and Le Corbusier, and featured in some prominent installations like Castel Béranger, La Mission d'Algérie, and in the façade of the Mumm caves. His bricks are rare today and existing installations even rarer, although careful demolition of old buildings occasionally results in large lots of bricks for sale. Like all glass bricks, including modern ones, they can't be replaced once damaged, so old installations often have unsightly patches.

Other Glass Bricks:


Glass blocks by Deutsche Luxfer Prismen-Gesellschaft	Marke Faust glass blocks by Deubener Glaswerke	Glass blocks by Siemens of Dresden	Vera-Lux glass blocks by Glasfabriek Leerdam
Another early type of glass brick made by Deutsche Luxfer Prismen-Gesellschaft, Deubener Glaswerke, Siemens, Glasfabriek Leerdam, and Gaston Blanpain-Massonet were unsealed and shaped much like early LEGO bricks. They lacked a bottom surface, so had problems with condensation, dust collection and calcification on their interior surfaces, which could never be cleaned.			Astral glass block by Gaston Blanpain-Massonet


Left: Bottle-bricks were also tried; they were BIM like bottles, but rectangular, and with punts matching their necks. The bricks shown (a gift from Taco Hermans) are unidentified, marked only with "Pat. ang." (Patent Angemeldet = Patent Pending). Their sides are lightly textured to increase the mortar bonding area, and like the LEGO-style bricks, they are not sealed, which also results eventually in contamination of their interior surfaces. Right: In 1963, Alfred Heineken designed a bottle of similar form, his "World Bottle" (WOBO), though instead of being purpose-made for construction, it was a beer bottle which could be re-used once empty. Heineken is at it again, experimenting with their Cube bottle of 2008; its design goal is more efficient use of transportation/shelf space, but it could also be re-used for construction.

Shapes: Four basic shapes were produced: square (#5, 6, 10½), a lozenge or watch-and-band shape (#8), squashed hexagon (#9), and a regular hexagon (#7, 7½, 10 and 11). All tessellate, forming a repeating pattern that completely fills a plane. #8 was the most popular shape and so is the most common now, followed by #9 (also fairly common), then regular hexagon and square, which are rare; I estimate the ratio at about 100:50:5:1. To fill a rectangular opening, non-square styles were also made in ¾, ½ and ¼ sizes. A ¾ brick finished the long side, a ½ brick finished the short side, and a ¼ brick finished a corner.

Colors: Most bricks were light aqua (halbweiss = "half-white"), the usual color of glass made from common sand which has iron contamination (which is most sands, as any child who's played in a sandbox with a magnet can attest), but other colors were available at extra cost: clear (aka "white") for improved light transmission, and decorative colors amber, green, blue and (opal) milkglass (all colored in the mass). A red brick was made by casing a clear brick in a thin layer of expensive, gold-ruby glass; they were more than twice the cost of other colors. The patent talks of coloring "either in the mass or by coating or covering them inside or outside in full or in part with layers of metal or paint"; additional ornamentation by sand-blasting, cutting and engraving, or acid etching is also mentioned, but I have yet to see these variations.

Finis: Modern-style two-part fused glass blocks were perfected in the 1930s, more than forty years after Falconnier's bricks were introduced. Around the same time, Belgian company Etablissements Gaston Blanpain-Massonet was was still producing bricks in the #8 and #9 patterns (always the most popular), as well as glass bricks in the style of Glasfabriek Leerdam. Siemens in 1933 was still making Falconnier styles 8, 9 and 10 (which they call types 1, 2 and 3), but with sides modified to interlock, and the ca.1950 A. G. Erste Böhmische Glasfabrik catalog lists styles 6, 7a, 8 and 9, plus some modifications. Today, almost 140 years after their introduction, Falconnier bricks are once more being produced by Luxfery in Prague (Czech Republic), Harzkristall in Derenburg (Germany) and NWGlass-lab in Saint Petersburg (Russia)!