Obsidian is a kind of black glass formed when the heat of a volcano melts the silica material in sand.

VOA: special.2009.09.16

Knitting is a way of creating clothing by looping together long thin pieces of material such as cotton or wool.

VOA: special.2009.04.08

The difference is that the printer builds a three-dimensional scaffolding out of a sugar-based material called a hydrogel.

VOA: special.2010.10.19

If there is only a small amount of rot, the dead material can be cut away.

VOA: special.2010.06.08

A comet is a huge ball of frozen gas and dust that often releases a long trail of material as it nears the sun.

VOA: special.2009.09.30

"One of the benefits is it's a relatively inexpensive renewable material that's readily available."

VOA: special.2009.10.05

A telomere is a structure of genetic material.

VOA: special.2009.12.08

So,yes,there is a threat particularly of the use of radioactive material, although we have no specific evidence indicating any capability at this time."

VOA: standard.2009.05.01

But the acquisition of radioactive material for a so-called 'dirty bomb,' which is radioactive material that is dispersed with a conventional explosive device, that is not that challenging.

VOA: standard.2009.05.01

One early submission is a dice game made of scrap material by an inmate who also included detailed, handwritten instructions on how to play the game he invented in his cell.

VOA: standard.2009.10.21

"The doctor appears one way, in scene four it's another way, in scene 10 it's something else and it is something that intrigued me a great deal so I sort of gave myself to the material along with the actors.

VOA: standard.2010.02.27