What's the noun for agate? Here's the word you're looking for.
agate
(countable, uncountable, mineralogy) A semi-pellucid, uncrystallized variety of quartz, presenting various tints in the same specimen, with colors delicately arranged in stripes or bands, or blended in clouds.
“Weimer dumped ham and onions into an agateware basin, and set it on the table.”
“Agateware are simulations of natural agate stones and these coloured ceramics create an optical illusion.”
“The Agateware Bowls, 2011, of the exhibition have a looser, slightly more random feel to them and are the beginnings of a new direction for Svendsen.”
“These include aquamarine, chrome diopside, diamond, jade, labradorite, forsterite, opal, pyrope, variscite, and many unique agates and jaspers.”
“The whole was embroidered with hundreds of pearls laced with two agates, twelve chrysolites, twelve garnets, a gold-mounted sapphire and a large pendant pearl.”
“In the same limestone there are enormous beds of chert, agates, and carnelians.”