The innermost moon of Martok is a shepherd moon for the gas giant's single ring. It resembles Io (the moon of Jupiter), in that it is volcanically hyperactive, covered in lava flows in the hot areas and various rocky elements in between. It is smaller than Io, though, only barely large enough to form itself into a sphere (and even then, an elongated one). Its core is heated up from tidal forces of Martok's gravity. It seems likely that a significant portion of the ring's material comes from volcanic material ejected from Guraza. Guraza is rich in a number of minerals that are useful to Bactaran spacefaring technology, and mining it for these materials was one of the early objectives of the space program. Mining Guraza is dangerous work, though, and mining the Solar System's asteroid belt proves a more attractive option once available.
The `TMP` given here refers to the majority of the surface; near active volcanoes, it can reach as high as `TMP` 9.
Etymology fun fact: The name "Guraza" is very similar to the Bactaran word for "fire".