Hellstone Bar. Hellstone Bars are made from 1 Obsidian and 3 Hellstone at a Hellforge. They are used to create Hellstone Tier items. Items made from Hellstone Bars are the highest quality craftable pre-hardmode items that require bars.
Unitary elastic means that elasticity is equal to 1. In case of price elasticity of demand, e = 1 implies that the percentage change in quantity demanded is equal to the percentage change in price of the commodity. Demand Elasticity is obviously negative. Elasticity = percentage change in quantity demanded / percentagechange in price. Even though perfect real life examples would be tough to list, a close example can be a 1$ increase in price of a good leads to a unit fall in its quantity demanded.
The elasticity of demand (Ed), also referred to as the price elasticity of demand, measures how responsive demand is to changes in a price of a given good. More precisely, it is the percent change in quantity demanded relative to a one percent change in price, holding all else constant (ceteris paribus). Demand of goods can be classified as either perfectly elastic, elastic, unitary elastic, inelastic, or perfectly inelastic based on the elasticity of demand.