Minerals and Metals in Ancient India v1.c25.s6.17

v1.c25.s6.17

The literary references to the chalcedony group of gem-minerals such as agate, carnelian, onyx, sard, sardonyx and their uses in ancient India would be discussed in Vol. II chapter 7. Agate and carnelian were mined, processed and used even in the Pre-Harappan times. Yellowish varieties containing hydrated ferric oxide used to be dehydrated on heating and thus reddened to beautiful carnelian in India for centuries in an age-old practice.