All our natural solid boulder opals go through multiple quality checks over time before being released for sale. Any boulder opals that do not pass these quality control checks because of natural inclusions or faults are classed as our SECONDS. Opal seconds should always be declared as such, prior to purchase, and are always valued at much lower prices. Please note that we do NOT sell cracked or crazed stones, as they are virtually worthless. Normally we only sell our boulder opal seconds at trade shows, but for a limited time only we have made them available here for you! They are exclusive to our website.