Dutch guilder
The Dutch guilder was once regarded as a petrocurrency due to its large quantities of natural gas and North Sea oil exports. The Dutch Guilder strengthened greatly in the 1970s, after OPEC began a series of price hikes throughout the decade that consequently increased the value of all oil-producing nations' currencies. However, as a result of the appreciation of the Guilder, industrial manufacturing and services in the Netherlands during the 1970s and into the 1980s were crowded out of the larger national economy, and the country became increasingly non-competitive on world markets due to the high cost of Dutch industrial and service exports. This phenomenon is often referred to in economics literature as Dutch disease.