Gold lends itself to being easily alloyed with a number of different metals. Yellow gold is gold alloyed with silver and copper. In rose gold, the concentration of copper is higher, whereas, in green gold, it is silver that has the higher concentration. Red and pink gold are formed by varying the silver and copper amounts. White gold is an alloy with palladium or nickel. Blue gold is formed with indium or gallium; purple gold is made using aluminum. ...
The Price-Specie-Flow Mechanism The price-specie-flow (PSF) mechanism is the extension of the quantity theory of money (QTM) to a multi-country scenario. Proponents of the end-neutrality of QTM often implicitly assume a closed economy. But when nations trade amongst each other, the injection of monetary units in a nation can, instead of putting upward pressure on local prices, promote imports, and thus cause an outflow of money, in the short term. The price-specie-flow mechanism accounts for these dynamics. ...
A price is simply a ratio of something in terms of something else. It need not necessarily be in terms of a fiat currency. The price of a certain watch may be ten pairs of a certain brand of shoes, or equivalently, an hour of consulting service of a certain expert, and so on. The ratios in terms of some goods become more prevalent due to their characteristics: durability, recognizability, divisibility, scarcity; these goods begin to acquire monetary recognition as individuals start accumulating them for the express purpose of exchanging them (as opposed to consuming them). These goods are traded more frequently than other goods due to their utility as media of exchange. The most traded good, thus, emerges as money, and market participants find it convenient to denominate prices in terms of this money, which, historically, has been gold. ...