Though some hand cut German agates were distributed in small Master Marble boxes at the 1934 Chicago World's Fair, production of these marbles had effectively ceased around 1925.Agates are composed of chalcedony, a fibrous quartz, that formed concentric layers (bands), mostly in lava flows.
Specific names have been applied to agate marbles, depending on their color.
Therefore, after 1813 agate workers began heating the agates in ovens to achieve the same effect.
This heating changed the color in the stone because the ferric oxide impurities would react to the high temperature.
It was kept moving by a water wheel attached to a set of cogwheels to quicken the number of revolutions.
Hand cut agates are typically faceted, as they were ground by hand into spheres.