Decentralized Gold holding and Crypto backed token shares

I have been researching for quite sometime advancing the use of cryptos to engage the average person who should be able to have a multi role whether to be an exchange, hold, loan and most importantly hold rare metal assets in addition to crypto assest.

So i took the initiative to build on what BitShares MPA (Market Pigged Assets) and i hope the community is able to contribute on if and how it can be done.

The idea is to create an index (asset) with a price feed of a combination of Crypto Assets + physical gold market price (based on what the holders claim to have in actual physical gold)

Lets assume we created an asset X

Investors invested a (value of)  1 bitcoin  or for the sake of the example 1,000 usd

I said (value of) because investors have a choice of holding gold and investing at the same time.

The investor will say that he/she will invest a total value of 1 Bitcoin or 1,000 usd  split between 200 USD worth of gold (5 grams) stored at his location (free to choose) and 800 USD worth of bitcoin  

In return the smart contract will provide him 1000 Tokens (assuming one token is one USD) 600 USD of those tokens are withheld as a collateral for the gold he or she is supposed to be holding.

The held collateral is actually held for the price of (  (gold price* weight of gold * 2 ) + (gold price * weight of gold) )

Additionally, the person is able to borrow Tokens to sell to someone either in CASH or in GOLD in any other crypto (market). However, there is always the requirement to borrow Tokens one must satisfy the collateral held for the borrow in terms of gold price or actually holding.

Lets assume the worst case scenario now where the price of gold actually tripled (3x) and all the Token holders were unable to cover their collateral in a reasonable period, so that all their tokens that were put as a collateral was called and redistributed to the holder(s) of the tokens, what is actually the outcome ?

There is a high probability the last remaining holder has gold and certainly will own all the actual crypto held in the smart contract.

I do believe that such combination allows markets without access to banking to thrive. I am not sure if this was done before but i would want to know.