Removing calcite from agates is an easy process. Calcite is found all around the world. It forms from rainwater and turns into limestone. Agates is a shiny, volcanic rock. A common form of agates is quartz. Calcite builds up around the agates covering the natural shine of the agates. Calcite can be removed from agates using an acetic acid solution. Vinegar is a mixture of acetic acid and water. Vinegar can be found at grocery stores and hardware stores.
Removal of calcite from agates
Mix one part of vinegar with one part of distilled water in a bucket.
Place the agates in the solution. Let the agates sit for twelve hours.
Dry the vinegar off the agates using a rag. Pour three cups of milk over the agates. The milk will neutralize the acetic acid from the vinegar.
Wash the agates with distilled water, then rub gently with a sponge. This will remove any remaining calcite from the agates.