What is a metal, for the purpose of a Forge cleric's Artisan's Blessing ability?

Question

The Forge Domain cleric gets the Channel Divinity option Artisan's Blessing at 2nd level (XGtE, p. 19; emphasis mine):

You conduct an hour-long ritual that crafts a nonmagical item that must include some metal: a simple or martial weapon, a suit of armor, ten pieces of ammunition, a set of tools, or another metal object. The creation is completed at the end of the hour, coalescing in an unoccupied space of your choice on a surface within 5 feet of you.

The thing you create can be something that is worth no more than 100 gp. As part of this ritual, you must lay out metal, which can include coins, with a value equal to the creation. The metal irretrievably coalesces and transforms into the creation at the ritual’s end, magically forming even nonmetal parts of the creation.

The ritual can create a duplicate of a nonmagical item that contains metal, such as a key, if you possess the original during the ritual.

From the Wikipedia article on metal:

A metal [...] is a material that, when freshly prepared, polished, or fractured, shows a lustrous appearance, and conducts electricity and heat relatively well. [...]. A metal may be a chemical element such as iron, or an alloy such as stainless steel.

In physics, a metal is generally regarded as any substance capable of conducting electricity at a temperature of absolute zero. [...]

In chemistry [...] Around 95 of the 118 elements in the periodic table are metals (or are likely to be such). The number is inexact as the boundaries between metals, nonmetals, and metalloids fluctuate slightly due to a lack of universally accepted definitions of the categories involved.

Then, on the periodic table, we can find that almost everything is a metal:

• Alkali metals.
• Alkaline earth metals.
• Transition metals.
• Post-transition metals.
• Lanthanides.
• Actinides.

And in the common speech:

• Base metal.
• Precious metal.
• Noble metal.
• Non-ferrous metal.

So, I was wondering, what is considered "metal" for D&D 5e? What materials (metals) is the Artisan's Blessing able to transmute?

Answer 1

Use common meaning for metal

E.g. a common definition:

a solid material that is typically hard, shiny, malleable, fusible, and ductile, with good electrical and thermal conductivity (e.g., iron, gold, silver, copper, and aluminum, and alloys such as brass and steel).

D&D is not a chemistry engine

Along the lines of "D&D is not a physics engine.". It is also not a chemistry simulation.

Answer 2

Traditionally, this is a matter of interpretation for the DM.

D&D 5e lead designer Jeremy Crawford has often stated that words not defined in the game rules should be interpreted to use the commonly understood English meaning of the word. When this is ambiguous, as in all ambiguous rules situations, the DM decides.

For example, in this tweet, Crawford says:

The DM decides how generously to interpret words like "ground." Unless we redefine or focus a word, we use it in its idiomatic English sense, knowing that some words are open to creative interpretation.

At the time this tweet was made in 2017, Wizards of the Coast official policy was to consider Crawford's tweets to be canonical interpretations of the D&D rules. However, that policy has since changed so that only the Sage Advice Compendium is official, and Crawford's rulings are merely opinions of the original designer, although they still carry much weight with players.

One might argue that, since you're limited to a value of 100 gp, you are limited to materials which you could normally buy in this world. Aluminium and magnesium appear in The Temple of Elemental Evil, and an orange dragon with a sodium breath weapon appears in Dragon #248, but whether the people of that world consider sodium a "metal" is another matter, and whether anyone could harvest it for as little as 100 gp is another matter entirely.