Automobiles may use gold for heat shielding. McLaren uses gold foil in the engine compartment of its F1 model. [209] Mallan, Lloyd (1971). Suiting up for space: the evolution of the space suit. John Day Co. p.216. ISBN 978-0-381-98150-1. Origin Gold production in the universe Schematic of a NE (left) to SW (right) cross-section through the 2.020-billion-year-old Vredefort impact structure in South Africa and how it distorted the contemporary geological structures. The present erosion level is shown. Johannesburg is located where the Witwatersrand Basin (the yellow layer) is exposed at the "present surface" line, just inside the crater rim, on the left. Not to scale. You get gold quality in the form of karats. Karats refer to the measure of the purity of gold ranging from 1 to 24. Typically, you will find it recorded on the gold jewellery piece such as 14K, 22K or 24K. You can get its percentage purity by dividing any of these numbers by 24. If you have 24K, you get 1.0 which means 100 percent pure. The refinement of gold should only be done by professionals. Any refinement undertaken at home carries serious risks and should be supervised by someone with experience to mitigate the risks.

Aleklett, K.; Morrissey, D.; Loveland, W.; McGaughey, P.; Seaborg, G. (1981). "Energy dependence of 209Bi fragmentation in relativistic nuclear collisions". Physical Review C. 23 (3): 1044. Bibcode: 1981PhRvC..23.1044A. doi: 10.1103/PhysRevC.23.1044. Revere, Alan (1 May 1991). Professional goldsmithing: a contemporary guide to traditional jewelry techniques. Van Nostrand Reinhold. ISBN 978-0-442-23898-8.Further information: History of money Two golden 20 kr coins from the Scandinavian Monetary Union, which was based on a gold standard. The coin to the left is Swedish and the right one is Danish. Heike, Brian. "Formation of Lode Gold Deposits". Arizona Gold Prospectors. Archived from the original on 22 January 2013 . Retrieved 24 February 2021. Gold does not react with sulfur directly, [41] but gold(III) sulfide can be made by passing hydrogen sulfide through a dilute solution of gold(III) chloride or chlorauric acid. LIGO and Virgo make first detection of gravitational waves produced by colliding neutron stars" (PDF). LIGO& Virgo collaborations. 16 October 2017. Archived (PDF) from the original on 31 October 2017 . Retrieved 15 February 2018.

The concentration of free electrons in gold metal is 5.91×10 22cm −3. [188] Gold is highly conductive to electricity and has been used for electrical wiring in some high-energy applications (only silver and copper are more conductive per volume, but gold has the advantage of corrosion resistance). For example, gold electrical wires were used during some of the Manhattan Project's atomic experiments, but large high-current silver wires were used in the calutron isotope separator magnets in the project. In recent years, gold has been used as a symbol of pride by the autism rights movement, as its symbol Au could be seen as similar to the word " autism". [212] Harjani, Ansuya (18 February 2014). "It's official: China overtakes India as top consumer of gold". CNBC . Retrieved 2 July 2014. de Vaan, Michel (2008). Etymological Dictionary of Latin and the other Italic languages. Leiden: Boston: Brill. p.63. ISBN 978-90-04-16797-1. Wedding rings are typically made of gold. It is long lasting and unaffected by the passage of time and may aid in the ring symbolism of eternal vows before God and the perfection the marriage signifies. In Orthodox Christian wedding ceremonies, the wedded couple is adorned with a golden crown (though some opt for wreaths, instead) during the ceremony, an amalgamation of symbolic rites. [ further explanation needed]Johnson, P. B.; Christy, R. W. (1972). "Optical Constants of the Noble Metals". Physical Review B. 6 (12): 4370–4379. Bibcode: 1972PhRvB...6.4370J. doi: 10.1103/PhysRevB.6.4370. O'Connell, Rhona (13 April 2007). "Gold mine production costs up by 17% in 2006 while output fell". Archived from the original on 6 October 2014. Unlike sulfur, phosphorus reacts directly with gold at elevated temperatures to produce gold phosphide (Au 2P 3). [42] At the London Gold Centre, they have a team of experienced professionals who have been trained in the art of melting gold. They use state-of-the-art equipment to ensure that the process is safe and efficient. They can also provide advice on the best way to melt your gold, depending on what you want to do with it.

In Islam, [117] gold (along with silk) [118] [119] is often cited as being forbidden for men to wear. [120] Abu Bakr al-Jazaeri, quoting a hadith, said that "[t]he wearing of silk and gold are forbidden on the males of my nation, and they are lawful to their women". [121] This, however, has not been enforced consistently throughout history, e.g. in the Ottoman Empire. [122] Further, small gold accents on clothing, such as in embroidery, may be permitted. [123] What Are the Different Purities of Sovereign Gold Coins?". goldsilver.com . Retrieved 29 March 2021. Arblaster, J. W. (1995). "Osmium, the Densest Metal Known" (PDF). Platinum Metals Review. 39 (4): 164. Archived from the original (PDF) on 18 October 2016 . Retrieved 14 October 2016.

The gold should be placed into a crucible. Then, put the crucible on a fireproof surface, and direct a torch toward the gold within the crucible. If you add the chemical borax to the gold first, you can melt it at lower temperatures, which might be needed if you’re using a torch. Upon determining the gold purity, make sure to get its measurement on a scale. For gold prices, they are often quoted based on troy ounces. A troy ounce is equivalent to 31.1g. This way, it will be easier to divide the current price of your gold item by 31.1 to obtain its cost per gram. The Price : Gopher, A.; Tsuk, T.; Shalev, S. & Gophna, R. (August–October 1990). "Earliest Gold Artifacts in the Levant". Current Anthropology. 31 (4): 436–443. doi: 10.1086/203868. JSTOR 2743275. S2CID 143173212. Corner, B.; Durrheim, R. J.; Nicolaysen, L. O. (1990). "Relationships between the Vredefort structure and the Witwatersrand basin within the tectonic framework of the Kaapvaal craton as interpreted from regional gravity and aeromagnetic data". Tectonophysics. 171 (1): 49–61. Bibcode: 1990Tectp.171...49C. doi: 10.1016/0040-1951(90)90089-Q.