UV spectra of the bright sungrazing comet C-2003K7 detected at 2.37 R sun above the Sun surface by the Ultraviolet Coronagraph Spectrometer (UVCS) during the daily synoptic scan show bright lines of H I Ly?, Si III ? 1206, and C III ? 977. The derived outgassing rate is an order of magnitude larger than those of the other sungrazers observed by UVCS. Analysis of the spectra suggests that the comet broke apart into smaller pieces before it reached the UVCS slit. The observations provide lower and upper limits to the values of the Si III/C III ratio, in the range 8-22. The ratio indicates a larger abundance of silicates in the cometary dust as compared to organic refractory materials.
