2nd coral found with other

[firehorse12]

Is this coral?

 

[nomad1]

This is not coral. This appears to be voids in a rock with secondary filling of either calcite or quartz. Can you see if the small crystals are hexagonal. If they are it is quartz.

 

[nomad1]

Taking a second look they crystals look like dog tooth spar (calcite). A small drop of dilute hydrochloric acid fizz if it is calcite.