Investors will soon be able to invest in wholesale diamonds. The Singapore Diamond Exchange, founded last year, will open trading on the precious gems in July. Exchange officials hope to trade $100 million in diamond portfolios within five years.

The diamond exchange will only handle trading, not the stones themselves, which will be held by custodian companies. Individual investor accounts will be managed by a partnership between the Exchange and IDEX Online, the New York Times reports.

The Exchange hopes to persuade investors to set up $1 million diamond portfolios, though as little as $250,000 is required to begin a portfolio. Quarterly auctions of diamonds from Exchange suppliers will be held to investors.

Diamond investors will receive quarterly portfolio reports and valuations based on IDEX Online indexes.

Backers of the Diamond Exchange note that diamonds represent a stable investment for high-net-worth individuals, having largely avoided the volatility of other investments in light of recent economic events in Europe and elsewhere. Prices in the gem market in general have been relatively stable, especially compared to stocks.

Since its launch almost eight yeas ago, the IDEX Online Polished Diamond index has soared almost 40%. During that same time, the S&P 500 index increased by 26%.

New players are entering the market. Harry Winston (NYSE:HWD) created a diamond investment fund last year with $100 million in funding. Rapaport Group and IndexIQ have announced plans to launch investment funds or trusts for diamond trading.