Rare earths may be the "sexy" strategic materials of the 21st Century, but in the 1st Century, it was tin. Tin was necessary for producing bronze, which was considered the metal of war. As one historian put it, "Gold and silver could finance a war, but bronze could win it." Bronze was the first metal that man could use to make non-corrodible tools and weapons.

Good as bronze was, there was a critical shortage of the tin necessary to make the alloy. The cassiterite placer deposits of the Mediterranean area were quickly exhausted and there is evidence that tin was even being brought west in caravans from India and Asia. Tin was an expensive and valuable commodity.

Although iron weapons were available and cheaper, they were softer than well made bronze weapons. Wrought iron has a Vickers hardness of 80. It also rusted and didn't keep an edge. Roman era steel was very expensive and has a hardness of 140.

Regular bronze had a hardness of 90, didn't rust and kept a sharp edge. With hammering, bronze's hardness could be raised to 228. Needless to say, those who could afford it preferred bronze swords, while the average soldier had to make do with an iron one.

It wasn't just swords that required bronze. Helmets, armor, and shields contained bronze. Even the solder used to manufacture the military equipment required tin. Roman officers also preferred shiny bronze to dull iron because it made their uniforms and armor more attractive. It also made them stand out on the battlefield and allowed them to be a visible rally point for their men.

This posed a problem. Tin deposits in southern Europe were scarce and small. The mines in Sardinia and Tuscany were exhausted. When Julius Caesar invaded Gaul (France) in 57 BC, one of the strategic objectives was to secure more tin supplies.

While there were some Northern European tin mines, they were far inland and took a long time to get to ports and into the hands of Rome's "military industrial complex." That's why the tin deposits in what is now Cornwall, England was so important. At about the time Christ was born; Roman writer Diodorus Siculus described tin mining in Britain. "They that inhabit the British promontory of Balerion by reason of their converse with strangers are more civilized and courteous to strangers than the rest are. These are the people that prepare the tin, which with a great deal of care and labor, they dig out of the ground, and that being done the metal is mixed with some veins of earth out of which they melt the metal and refine it."

The process for mining and refining cassiterite at this time was simple. Cassiterite was easy to detect in a mine because the small crystals had a high refractive index and sparkled. The ore would be crushed at the surface, and the washed concentrate might even be shipped a distance to a central place that had enough trees for smelting. The mined cassiterite would be mixed with charcoal and heated in small crucibles until the tin melted into globules. The product of the smelting would be crushed and the tin globules washed out.

Since Rome hadn't conquered Britain yet, it was the Phoenicians who controlled the shipping. And according to tradition, it was a Joseph of Arimathea who visited Cornwall frequently, owned several tin mines, and shipped the raw tin on Phoenician ships. If it has been awhile since you went to Sunday School, it was Joseph who asked Pilate for Christ's body after Christ was crucified. He then buried Jesus in his own tomb. Little is historically known about him except that he was rich, he was a follower of Christ, and he had the nerve to ask for Christ's body.

This brings up an interesting question. If the disciples were hiding for fear of being jailed or crucified, why was Joseph willing to go to the Roman procurator, admit he was a disciple of Jesus, and then ask for the body?" Maybe it was because Joseph controlled one of the most important metals in the Roman Empire. Pilate wasn't stupid.

We have to rely on tradition and early Christian writers to track what happened to Joseph of Arimathea after the death and resurrection of Jesus. According to tradition, Joseph leaves Jerusalem a few years after Christ's death and resurrection and heads back to his mine holdings in Cornwall in 37 AD, where he founds the first church at Glastonbury.

Whatever the truth, when the Romans did conquer Cornwall in order to control its tin mines, it appears that Christianity was already there. The church credits Joseph with the introduction of Christianity to Britain and in the Catholic Church; he is the patron saint of tin miners. While some scholars doubt some of these stories, there are writings of early church fathers that indicate it is true.

Interestingly enough, the story of British tin is not over, even if it isn't the strategic metal it once was. Although the last British tin mine closed 14 years ago, the higher prices of tin have encouraged Celeste Copper Company to reopen the South Crofty Mine in Cornwall in the next few years. Geologists estimate about $2 billion of tin is still recoverable at the mine.