6 (SIX) Agate Coaster - Brown Black Natural Tones Agate Coasters Rock Paradise COA (AM9B1) 6 (SIX) Agate Coaster - Brown Black Natural Tones Agate Coasters Rock Paradise COA (AM9B1) This Listing is for 6 (SIX) Agate slice with gold electroplated edges. STOCK PHOTO. Agate Slices can vary slightly in overall characteristics because those are natural formations. Those agate slices have between 2.5 to 3.5 inches. Perfect for jewelry making, as a pendant setting and for all kinds of arts and crafts.