Gold

Vanilla
on the Minecraft Wiki

Flaxbeard's Steam Power
Flaxbeard's Steam Power only adds the plate variation of the Gold material. The Gold Plate can be created by throwing Gold Ingots into a heated Crucible, and then pouring that molten metal into a Mold with a Plate Mold. Six nuggets are used in the creation of a Plate, which makes it unable to be used in other mod's recipes requiring their own Gold Plates.

GregTech 5
Small Gold Ore can be found at mining level 1, and regular Gold Ore can be found at mining level 2.

Esteemed Innovation
Esteemed Innovation adds the Thin Plate variation of the Gold material. The Thin Gold Plate can be created by melting Gold in a heated Crucible, and then pouring that molten metal into a Mold with a Plate Mold.

LightningCraft
LightningCraft adds a Rod form of Gold.

Tesla Core Lib
Tesla Core Lib adds a Sheet, Powder, and Gear form of Gold.