Honeycomb fossil coral (often scientific. Because honeycomb fossil coral gets its durability from being replaced by quartz, it behaves much more like an agate than a standard soft reef coral. ) is a 400+ million-year-old prehistoric coral.
30 Ct 6X21X28 mm Natural Designer Dendrite Opal Fancy Cabochon Gemstone PE-222
A real dendritic opal will not have bright flashes of rainbow colors; if it does, you are likely looking at precious opal or a simulant. Real dendritic opal has intricate, unpredictable, and entirely unique branch-like patterns.
58 Ct 8X26X34 mm Natural Designer Dendrite Opal Oval Cabochon Gemstone PE-60
A real dendritic opal will not have bright flashes of rainbow colors; if it does, you are likely looking at precious opal or a simulant. Real dendritic opal has intricate, unpredictable, and entirely unique branch-like patterns.