The binary gold halides, such as AuCl, form zigzag polymeric chains, again featuring linear coordination at Au. Most drugs based on gold are Au(I) derivatives.Au(III) (referred to as the auric) is a common oxidation state, and is illustrated by gold(III) chloride, Au2Cl6. The gold atom centers in Au(III) complexes, like other d8 compounds, are typically square planar, with chemical bonds that have both covalent and ionic character. Gold(I,III) chloride is also known, an example of a mixed-valence complex. Gold does not react with oxygen at any temperature and, up to 100 °C, is resistant to attack from ozone.
Similarly, gold is associated with perfect or divine principles, such as in the case of the golden ratio and the golden rule. Gold is further associated with the wisdom of aging and fruition. The fiftieth wedding anniversary is golden. A persons most valued or most successful latter years are sometimes considered "golden years". The height of a civilization is referred to as a golden age. Religion
In some forms of Christianity and Judaism, gold has been associated both with the sacred and evil. In the Book of Exodus, the Golden Calf is a symbol of idolatry, while in the Book of Genesis, Abraham was said to be rich in gold and silver, and Moses was instructed to cover the Mercy Seat of the Ark of the Covenant with pure gold. In Byzantine iconography the halos of Christ, Virgin Mary and the saints are often golden.In Islam, gold (along with silk) is often cited as being forbidden for men to wear. 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". This, however, has not been enforced consistently throughout history, e.g. in the Ottoman Empire.