Volcanic rocks are usually fine-grained or aphanitic to glass in texture. They often contain clasts of other rocks and phenocrysts. Phenocrysts are crystals that are larger than the matrix and are identifiable with the unaided eye.Rhomb porphyry is an example with large rhomb shaped phenocrysts embedded in a very fine grained matrix.Volcanic rocks often have a vesicular texture caused by voids left by volatiles trapped in the molten lava.henocrysts are crystals that are larger than the matrix and are identifiable with the unaided eye. Rhomb porphyry is an example with large rhomb shaped phenocrysts embedded in a very fine grained matrix. Volcanic rocks often have a vesicular texture caused by voids left by volatiles trapped in the molten lava.
The actual temperature in space is about 3Â°K (-270Â°C or three degrees Celsius above Absolute Zero). There are still molecules in space, just very few of them, and this is their temperature. Absolute zero is a theoretical temperature where the thermal kinetic energy of the molecules in a body goes to zero.
Surface temperature. Also, if a star has the same radius as the sun but a higher surface temperature, the hotter star exceeds the sun in luminosity. The sunâs surface temperature is somewhere around 5800 Kelvin (9980 o Fahrenheit).Thatâs 5800 degrees above absolute zero, the coldest temperature possible anywhere in the universe.etâs presume a star has the same surface temperature as the sun, but sports a larger radius. In that scenario, the star with the larger radius claims the greater luminosity. In the example below, weâll say the starâs radius is 4 solar (4 times the sunâs radius) but has the same surface temperature as our sun.