Cave onyx is a variety of banded calcite (CaCO3) formed in cave systems. According to Mindat it is often incorrectly shortened to just Onyx. However, true onyx is a quartz and is much harder (3 vs 7).
Shipping cost is based on weight. Just add products to your cart and use the Shipping Calculator to see the shipping price.
We want you to be 100% satisfied with your purchase. Items can be returned or exchanged within 30 days of delivery.