Versions:
-Minecraft Forge: 14.23.5.2854
-Industrial Renewal: 0.21.8

What happens:
Both Gematite block and item forms share the same oreIron OreDict key, which makes it possible to convert item form back to block form in Mek's Oredictionificator. Then you can break the block to get more items, convert each item back to a block, and so on.
When combined with OpenComputers and some coding, this cycle can be fully automated to produce free iron for nothing at really insane speeds (think about a Fortune III and Mending enchanted pick).

I think that Gematite block should have oreRichIron key rather than just oreIron. Or some other key, just to break the cycle.