With the exception of specific golden crosses (such as the fabled Flaming Cross of Goa), something called a Golden Cross is not actually a cross shape of anything; it is simply a term used in financial markets to describe a crossover involving a security's short-term moving average breaking above its long-term moving average. So now you know.
In heraldry, a gold cross is seen on the Coat of Arms of Pope John-Paul II and in the logo of the Pentecostal Assemblies of the World, but not in many other other ecclesiastical emblems.
It is seen, however, on St. David's flag and a few national flags. On the flag of Jamaica for example, the gold saltire cross signifies sunshine. On the Swedish flag (not much sunshine there) the cross is from a Coat of Arms and from the time when, in 1569, King John III issued a warrant that all Swedish battle flags should include a yellow cross.
But the Yellow Cross has not only been used in Swedish battles.
Soon after we imposed 'freedom' on Afghanistan in 2001, Sikhs and Hindus were forced to wear yellow armbands.1
On 1st September 1941, the Nazis decreed that all Jews over the age of ten within Germany, Poland and other occupied lands must wear a yellow Star of David. This identification made it easier for the Nazis to target individual Jews and instill fear and humiliation. Failure to wear the badge carried the death penalty. The yellow marking was not, however, an original idea by the Nazis.
Way back in the year 807, Abbassid caliph Haroun al-Raschid ordered all Jews to wear a yellow belt and hat. In 1179, the Third Lateran Council decreed that lepers must wear clothes marked with a yellow cross. Also in the Middle Ages, Cathar heretics were forced to identify themselves by wearing a yellow cross on their clothing, and Jews were forced to convert to Christianity and wear an identifying yellow cross.
During the First World War, a yellow cross was painted on gas shells to identify their contents. Yellow cross gas shells contained the volatile liquid dichlorethylsulphide, more commonly known as the blistering mustard gas. Although it had a death rate of just one or two percent, the gas was considered an effective weapon because it usually disabled rather than killed outright. Panicking and incapacitated soldiers are more of a hindrance to their army then dead ones.2
Other gases were used and their shells painted with different distinguishing colours. (See White Cross, Blue Cross and Green Cross.) Victims of the gassing prompted the formation of specialist medical corps and research organisations which continue today. (See Lorraine Cross and the American Lung Association.)
Even though it was outlawed by the Geneva Protocol of 1925, which prohibited the use of "asphyxiating gas, or any other kind of gas, liquids, substances or similar materials", mustard gas was used in the Second World War. After that it was used in Egypt against North Yemen in 1960s, Iraq against Iran and the Kurds in 1980s, and huge stockpiles remain around the world.
As of 2006, the U.S. Army still had thousands of tons of mustard agent awaiting destruction. (www.cma.army.mil/home.aspx) They are gradually disposing of this declared stockpile, in accordance with the Chemical Weapons Convention in 1993. This is, of course, a good thing. What is worrying is the word 'declared' and many countries including China, France, India, Iran, Japan, Libya, Russia, the U.K. and the U.S. still have chemical weapons production facilities. And if that's not horrible enough, several countries around the world still have an interest and capability of making biological weapons. (See Black Death Cross.)
Referring back to the yellow cross worn by Jews, this seems to have escaped the attention of the Swedish neo-Nazi group Gula Korset (Yellow Cross) who have adopted the yellow cross from their national flag. The Gula Korset support (as corsets do!) 'Aryans' serving prison sentences, publish ultra-right wing leaflets and organise rallies to spread their message. They use the yellow cross of the national flag as an attempt to add intellectual respectability to their hatred. (Fortunately for Sweden, as in most countries, such extremist groups represent only a tiny percentage of the population.)
But there's a golden lining to this poison gas cloud of the yellow cross:
In 1992, Professor Siegwart Horst-Gunther founded a humanitarian organisation to help children suffering in war zones. Many of these children and babies have been caught up in the chemical and radiological warfare. Working closely with the Red Cross and Red Crescent, they deliver aid to the needy all over the world. His organisation is called the International Yellow Cross.