Why is Silk so Valuble?

Why is silk so valuble? Silk is very valuble because only certain people have the abillity to make things out of silk. Did you know that silk is so valuble to china that anyone who trys to smuggle cacoon out of china would of been exicuted (note: that exacution was back in ancient china). Now adays if people do this they would probably end up in jail. Silk is VERY expensive, most people back in ancient china probably could not afford silk. Silk is an exrutiating long procces first you have to feed the silk worm on a raw diet of only mullberry leafes. Then you have to wait 3 to 4 weeks for it to make  a cacoon. Then you have to make the piece of clothing or other material you choose to make.