The phrase "ancient iron" is correct and usable in written English.
It can be used to describe iron that is from a very old period, often in historical or archaeological contexts.
Example: "The archaeologists discovered a collection of ancient iron tools that dated back to the Roman Empire."
Alternatives: "historic iron" or "old iron".
The ancient iron formations share many characteristics with modern limestones, which suggests that they accumulated in a marine environment.
Here's where the ancient iron atoms are crucial because blood is almost entirely water, yet hardly any oxygen will dissolve into pure water.
In his nearby grocer's kiosk, Hamad Kashef, 80, sits among open sacks of rice and nuts, an ornate and ancient iron scale in front of him.
An ancient iron safe, too heavy to move, occupies one corner of their floor-through loft; they use it as a liquor cabinet.
The larger of the two police stations that rebels said they seized on Tuesday lies near the old city of Aleppo and its ancient iron gate.
Along the hallway you can see the heavy dark beams that were part of the original construction, pitted with the marks of old chisels and embedded with seemingly ancient iron nails.
Figure 10 Phase equilibria of ancient iron-formation at 25°C in the Fe Si O H system using composition of Franklin Seamount vent fluid ([Fetotal] = 3.9 × 10-5m and [Si] = 3.4 × 10-4m).
Eventually, they concluded there was evidence for microfossils of ancient iron-oxidizing organisms.
Four of the regular transition elements were known to the ancients: iron (ferrum), copper (cuprum), silver (argentum), and gold (aurum).
The relationship to ancient cast iron mains speaks volumes about our infrastructure issues in this country.
I'm in a huge, ancient cast iron bath with crackled cream enamel, and I've decided to float on my back in the green water, piling the huge mounds of luscious fleshy seaweed all over me.
