Past Glass Facts have include entries on obsidian, tektites and fulgurites -- all naturally occuring geological forms of glass. Today's Glass Fact is about the amazing naturally occuring biological glass found in a truly bizarre, deep undersea sponge.
The Venus Flower Basket is constructed of an elaborate weave of glass (silica) strands. A recent article in Science magazine compares the natural engineering of the animal (yes, sea sponges are animals -- who knew?) with some of the best human engineering designs in use today.
Also of interest to scientists is understanding how the glass strands are grown in the cold temperatures of deep sea since modern fiber optics can only be produced at high temperatures.
(Very cool - but not really having anything to do with glass - fact: Certain shrimp mate and live within the Venus Flower Basket. Frequently, the sponge grows a "lid" that traps the shrimp pair -- who may continue to live and breed in their glass prison -- their offspring being small enough to escape the cage.)