Steel, Iron, and Copper

Was reading about Steel and how it's produced from Iron/ברזל on Wikipedia.

Apparently standard Iron (Fe) either comes with Oxygen as Iron Oxide (FeO3) or with Sulfur as Iron Sulfide (FeS2) (Fool's Gold). They then use Carbon (in the form of coke) to exchange the Oxygen/Sulfur with Carbon to make Steel. But I digress.

In any event thought to look up ברזל in the Torah and came across the following peculiarity:

It's a curse to have your earth like iron and your heaven's like copper yet a good thing if the earth has stones of iron and mountains from which to take copper. Strange.

והיו שמיך אשר על-ראשך, נחשת; והארץ אשר-תחתיך, ברזל

vs.

ארץ אשר אבניה ברזל, ומהרריה תחצוב נחושת

I also thought it uncanny how in the majority of places in Tanach, ברזל and נחשת seem to go hand in hand with each other. דוק ותשכח