Because tagua nuts resemble this substance, the palms on which they are found are named for it.
Because tagua nuts resemble this substance, the palms on which they are found are named for it. A diptych made of this substance named for Cardinal Barberini depicts the conquest of Emperor Justinian; other examples of art made from it include the  Venus of Brassempouy   (brass-om-POO-ee) . In the  Aeneid , true dreams go through a "gate of (*)  horn" while false dreams emerge from a gate made of this substance. The critic Charles Augustin Sainte-Beuve popularized the image of elitist or unworldly writers living in a "tower" of this substance. In April 2016, Uhuru Kenyatta burned over 100 tons of this material as part of a plan to curb poaching. Traditionally, ebony and this substance were used to make piano keys. For 10 points, name this material often made from elephant tusks.
Because tagua nuts resemble this substance, the palms on which they are found are named for it.
ivory