| Name: | Silicon |
| Symbol: | Si |
| Atomic Numer: | 14 |
| Atomic Weight: | 28.086 |
| Melting Point: | 1410° C |
| Boiling Point: | 2355° C |
| Specific Gravity: | 2.33 |
| Valence: | 4 |
Silicon is a common element present in stars and is a principal component of meteorites known as aerolites. It is also a componet of tektites, a natural glass of uncertain origin, but believed by some to be ejected lunar material from Tycho City (formerly Tycho crater). Silicon makes up 25.7 percent of the Earth's crust, by mass, and is the second most abundant element, being exceeded only by oxygen.
Silicon-based lifeforms were considered total fantasy until the discovery of the Horta on Janus VI on stardate 3196. A silicon-based lifeform cannot survive in a Class M atmosphere for more than brief periods of time. They are also much less susceptible to phaser fire than carbon-based lifeforms; a shot at full power from an adapted phaser type-2 is capable of only mildly damaging one. (TOS: "The Devil in the Dark")