This is a very unique and beautiful agate slab. I believe that some calcite grew into the agate, as can be seen on the left side of first photo. It would make a lovely display piece! It is almost 1" thick and 5" across in diameter. No flaws to note, this is in excellent condition just as it was when I purchased it. Please keep in mind that crystals have natural imperfections, and polished crystals such as this also are not perfect. I always point out if there are true flaws that have developed after I purchased the item. I have many crystals listed, and you can bundle multiple for a better price. I am open to considering all reasonable offers.