Here are several examples why the silver/gold/platinum/diamonds/shells standard won't solve much:
1) Any credit is a bet on the future. Say I am a bank and I only lend the gold coins I have in my vault. Somebody comes and asks for a loan of 10 gold coins. I need to trust that in the future that person can indeed pay me 10 gold coins + interest.
Even if I secure those 10 gold coins with a collateral I am betting the collateral will be worth 10 gold coins in the future.
Since I am not the only bank around, I can't ask an outrageously valuable object/piece of real estate as a collateral for 10 gold coins, because the borrower would go to another bank with lower demands. Which means that no matter what collateral I might get, it won't be much more valuable than 10 gold coins today. As such I am back to square 1, betting it would be still worth 10 gold coins in the future.
If my bet turns out to be incorrect, I have lost some of those 10 gold coins (or all of them) entrusted to me by the people who made deposits to my bank.
The gold standard can't prevent banks from going belly up. And during all that time currency was backed by gold, some banks went under.
2) People would make speculative bets with something else, not necessarily with currency. Look up the 16th century tulip bulb market crash or the 19th century stock market, bond market or real estate market crashes. Spain and several South American countries were invaded because they failed to pay their debts. In the 19th century the Ottoman Empire had to give the tax collection to a consortium of international banks, after defaulting on its sovereign debt, etc. During all that time currencies were backed by gold;
3) Gold, silver, platinum, shells are in finite quantity, human ingenuity is infinite.. Say the total quantity of precious metals is already allocated to various businesses when two young men, Steve Jobs and Bill Gates, come to ask for funding for their startups (Apple and Microsoft respectively). They can't get any funding because there's no precious metal left unused. The world would know no Apple and no Microsoft. Nor Ford, nor Boeing, and quite likely no Internet either.