Kairopan was an organic crystal found on the planet Kairos, which would be gathered by manual labour during the so-called Harvest of Kairos.
It was highly prized, available for one week only after the vernal equinox. During the time of the Liberator's visit, there an above average yield. This resulted in leaving the labourers and one of the guards behind to avoid overloading the shuttle.
Giant ant-like creatures on the planet sought the crystal to make silk, consuming the crystal in their mouths. They would pursue and kill anyone who possessed or even handled the substance. (TV: The Harvest of Kairos]