Glass is an extremely temperamental substance—it can go from innocuous receptacle to jagged weapon in a matter of seconds. Most glass art exhibited in galleries and museums embodies traits of the former, but Graham Caldwell goes for the jugular with a show that embodies the latter. His glass sculptures are inspired by thorns, antlers, teeth and spikes, protruding from the walls of G Fine Art as if to ensnare a patron in their shiny, translucent talons. Unlike Dale Chihuly, the most famous of the glassmakers, Caldwell eschews bright colors and soft forms for something a little more dangerous. You’ll be taken by his craftsmanship without thinking of him primarily as a craftsman (Caldwell has said before that he avoids showing with other glass artists for this reason). Not all of Caldwell’s glass is menacing, though. In the gallery’s project room, you’ll find several pieces that explore glass’ qualities as a reflective and refractive substance, duplicating themselves dozens of times over. Moon Jellies floats on a steel framework a variety of crystal globes, and like the ocean creatures that inspire them, the reflection of their scaffolding produces dozens of tentacles. A few other works have been declawed, like those comprised of glass ropes that are tangled and knotted together, looking quite like a Brice Marden painting re-imagined in 3-D. Caldwell’s work has the most bite, though, when he gives it a set of razor-sharp teeth. The exhibition is on view from 11 a.m. to 6 p.m. Tuesday-Saturday, to March 28, at G Fine Art, 1515 14th St. NW. Free. 202-462-1601.