Is it bling or a real ruby?
QUESTION What gemstones can be produced in a laboratory?
THEORETICALLY, all gemstones can be made artificially, but the most lucrative are rubies, sapphires and diamonds.
Ruby was the earliest to be made with any serious i ntent. However, its development was not aimed at the gemstone market, but as part of the early development of lasers.
The first laser was made in 1960 from a rod of synthetic ruby and it emitted red light.
This ruby was made by drawing solid crystal from a melt pot by a method invented by Polish scientist Jan Czochralski in 1915.
Ruby is simply crystalline aluminium oxide, known as corundum, and is clear when it is pure. A natural ruby has impurities of chromium and iron, which give it a luxurious red colour and varieties of shade.
A synthetic ruby has only chromium as the impurity, and this is added very exactly to give the correct energy levels for laser application, so it can easily be distinguished from a top-grade gem.
Sapphire is the same corundum as ruby, but can have a huge variety of impurities. Blue is produced by iron and titanium, but almost all other colours are available.
Synthetic sapphire is produced by several different processes and can be made in very large crystals weighing several kilos or as flat ribbons.
It is clear, so is unrecognisable from the gemstone. Being very hard, it is used as glass in the most expensive watches and as optical windows for LEDs. Titanium-doped sapphire is used in lasers.
Creating a synthetic diamond has exercised the minds of the gemstone i ndustry. Traditionally, i ndustrial diamond grit was manufactured by methods that imitate the geological conditions forming natural diamonds — extreme heat and pressure.
Developments in the early 1970s have allowed larger and more perfect crystals to be produced. Early synthetic diamond had nitrogen trapped in the crystal giving a yellow tinge, but this has been overcome, producing clear gems.
Synthetic diamond is now produced as a thin film by deposition from the cracking of carboniferous vapour. It is used as a coating on other materials to give the ultimate damage-resistant surface.
Keith Matthews, Ferndown, Dorset.
QUESTION Was the cadaver of a Pope once put on trial?
BETWEEN AD896 and AD903, there were seven popes. It was the beginning of an era i n the papal succession known euphemistically by the Roman Catholic Church as the Saeculum Obscurum or the Dark Age. It is more prosaically known as the Age of the Harlots.
The background was political turmoil: the collapse of the Frankish-dominated Carolingian empire, the emergence of a Holy Roman Empire, the split from the Byzantine East and battles over the Lombard throne in what is now Italy.
The election of Pope Formosus in 891 was fraught with infighting. He was promoted by the Spoletos headed by Guy III, Holy Roman Emperor, and opposed by the powerful Tusculani family.
Formosus became distrustful of his sponsors and invited King Arnulf of the East Franks to invade Italy. In 896, Formosus crowned Arnulf emperor, but while preparing to attack Spoleto, Arnulf was seized with paralysis.
Formosus died soon after, leaving the discord unresolved.
Boniface VI was made pope in April 896. He had a shady past, twice being defrocked by Pope John VIII for immorality. He died just 15 days into his papacy, supposedly of gout, but he was possibly murdered at the behest of the Spoleto faction.
In an extraordinary act of revenge, his successor Stephen VI had the corpse of Formosus disinterred seven months after his death, clad in papal vestments and seated on a throne to face papal justice. In what became known as the Cadaver Synod, Formosus was deemed unworthy of the pontificate, all his measures and acts were annulled, the vestments were torn from his body, the three fingers from his right hand used in consecrations were cut off and his corpse was thrown into the Tiber. In 897, 14 months after he became pope, Stephen was imprisoned and strangled in the night, possibly by his sponsors, the Spoleto faction. Colin Radd, Cardiff.
QUESTION Why did Mexican forces massacre Chinese immigrants in 1911?
ANTI- CHINESE sentiment emerged during the Mexican Revolution, which was the overthrow of the 31-year-long regime of Porfirio Diaz.
Under Diaz, Chinese immigrants had been encouraged to move to sparsely populated areas that were in need of economic regeneration.
Hard-working, frugal and mutually supportive within their own communities, they became successful farmers and entrepreneurs, running successful restaurants and bars. This stirred up local jealousies that found a violent outlet during the revolution.
On May 13, 1911, the revolutionary forces of Francisco Madero attacked the northern city of Torreon. The next morning, they entered the town. Following on the coat-tails of the soldiers came 4,000 people from towns and villages throughout the region.
They plundered the city, targeting businesses owned by immigrants. By the end of the day, 303 Chinese and five Japanese immigrants were dead.
Throughout the Mexican Revolution, Chinese immigrants were persecuted and killed, their businesses ransacked and communities threatened. Attacks continued even after the end of the revolution in 1920. Legislation restricted Chinese i mmigration, prohibited marriages between Chinese and Mexicans and segregated communities.
Diane Wilkes, Chesterfield, Derbys.
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