[en] This report presents the major results of an exhaustive study of the failure properties of crystalline and fused quartz when irradiated with many pulses of laser light at wavelengths from 1064, to 350 nm. Data is presented which shows that the bulk damage threshold for single-pulse irradiation varies little from one material to another and depends somewhat on the laser wavelength. On the other hand, the multiple-pulse damage properties are highly dependent on material, laser wavelength, spot size, pulse duration and pulse repetition rate. These results and the statistics of the multiple-pulse damage process show that it results from the accumulation of microscopic damage on each sub-catastrophic-damage threshold pulse. The repetition-rate dependence shows that the microscopic damage has a lifetime of the order of tenths of a second, and this suggests that this sort of damage may be the result of transient color-center formation