Rarity

Rarity is usually considered as a measure of how difficult to obtain or how valuable an item is. The color of the item name text gauges the rarity of an item, with White being the most common and Purple being the most rare. All items with rarity higher than White will not burn when in contact with lava (with the exceptions of Hellstone, Obsidian, Clay Pots, Fireblossom, and Fireblossom Seeds).

It should be noted that the rarity of many items can change a lot depending on their mods. Items with positive mods will have a higher rarity than the same items without mods, and the same goes the other way around.