Unreplaced

They were clearly formed by replacement of the schists particle by particle, as shown by the frequent preservation of the schist structure in a banding of the sulphide minerals, the residual shreds of unreplaced schist material in the ores, and the usual gradual transition from unreplaced schists to those completely replaced by massive sulphides.

At this same time, my copy began coming back to me uncorrected; words whited out and not replaced in the haste of a deadline remained unreplaced, spelling errors (and I don't mean "potatoe") remained uncorrected.