(ESO) How Does Ore Type Affect Refining Results?

June 8, 2014

In The Elder Scrolls Online, blacksmiths refine ore to produce a variety of crafting materials including ingots (the purer metal used to make weapons and armor), tempers (which upgrade items into different rarity classes), and trait gems (which add bonus stats to equipment). Naturally, refining Iron Ore yields Iron Ingots, Dwarven Ore yields Dwarven Ingots, and so forth.

However, most of the value of ore lies not in the ingots (which are a guaranteed drop), but in rarer by-products like Grain Solvents and Tempering Alloy. One way to improve the yield of these components is to allocate skill points to the Metal Extraction passive. But does the level of an ore also affect the kinds of tempers it produces? It seems like it ought to work that way, and more than one person in ESO zone chat was happy to tell us that obviously, higher-level ores dropped better tempers. We decided to find out for ourselves.

The Test

We bought/borrowed/gathered 20 stacks each of Iron Ore (the basic starter material found on the newbie islands) and Calcinium Ore (found in Veteran zones and used to make VR1-3 equipment). Using the same character (Rank 3/3 in Metal Extraction) for all operations, we refined all the ore and carefully tallied the amount of ingots, tempers, and trait gems dropped by each type of ore.

Ingots Stone Oil Solvent Alloy Any Temper Any Trait
Iron Ore 1704 32 21 13 7 73 61
Calcinium Ore 1694 21 25 14 8 68 66
P-Value 0.1397 0.6386 1.0000 1.0000 0.6756 0.6675

The P-values given above are the two-tailed P-values generated by Fisher’s exact test. We drew up contingency tables to compare the ores:

  • in terms of each individual temper type
  • in terms of their overall probability of dropping a temper item (of any rarity)
  • in terms of their overall probability of dropping a trait gem (of any type)

In no case was the difference in yield between Iron and Calcinium statistically significant; for Grain Solvent and Tempering Alloy (the real money-makers), the drop rates were virtually identical. It may be worth noting that the trait gems seemed to be more or less randomly distributed; 65 were for weapon traits while 62 were for armor traits. All sixteen types of gem showed up at least once.


Somewhat counterintuitively, Iron and Calcinium have virtually the same yield in terms of tempers and trait gems, despite the fact that Iron is available to the rawest recruit while Calcinium is abundant only at Veteran ranks. We see no strong reason to suppose that this relationship wouldn’t extend to other types of ore as well. If true, this accounts for the surprisingly narrow spread in prices offered by bulk ore buyers, who will often offer (for example) 12g per unit of Iron Ore but only 17g per unit of Calcinium Ore.

Of course, the ingots themselves will vary in value based on type  — as of this writing, Iron goes for about 6g/ingot, Calcinium about 10. The prices of tempers fluctuate, too. To account for all that, we’re building a calculator that incorporates the data from this experiment, so that the borrowers and lenders of ESO can size up a potential bargain based on current market rates.

Data for this post was gathered 5 Jun 2014 to 7 Jun 2014 using version 1.1.3 of The Elder Scrolls Online. It may not reflect changes introduced in subsequent patches of the game.

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