Main article: Islamic economics in the world
Further information: Early reforms under Islam and Islamic capitalism During the Islamic Golden Age, early forms of proto-capitalism and free markets were present in the Caliphate, where an early market economy and an early form of mercantilism were developed between the 8th-12th centuries, which some refer to as "Islamic capitalism". A vigorous monetary economy was created on the basis of the expanding levels of circulation of a stable, high-value currency (the dinar) and the integration of monetary areas that were previously independent. A number of economic concepts and techniques were applied in early Islamic banking, including bills of exchange, the first forms of partnership (mufawada) such as limited partnerships (mudaraba), and the earliest forms of capital (al-mal), capital accumulation (nama al-mal), cheques, promissory notes, trusts (see Waqf), transactional accounts, loaning, ledgers and assignments. Organizational enterprises independent from the state also existed in the medieval Islamic world, while the agency institution was also introduced during that time. Many of these early capitalist concepts were adopted and further advanced in medieval Europe from the 13th century onwards.  Riba
The word "Riba" means excess, increase or addition, which according to Shariah terminology, implies any excess compensation without due consideration (consideration does not include time value of money). The definition of riba in classical Islamic jurisprudence was "surplus value without counterpart", or "to ensure equivalency in real value", and that "numerical value was immaterial." During this period, gold and silver currencies were the benchmark metals that defined the value of all other materials being traded. Applying interest to the benchmark itself (ex natura sua) made no logical sense as its value remained constant relative...