When the fund launched in November 2012 I wrote about it -- noting it may not be an investor's best friend because of its narrowness, and that whenever the next recession comes along the fund is likely to be hard hit because of how sensitive jewelry purchases are to the economic cycle. For example, Signet Jewelers fell 80% during the last bear market. Another aspect of diamond purchases is the flight-to-safety aspect where people can effectively hide or park assets in diamonds because they are very small, yet very expensive. A fund investing in diamond companies should not be expected to offer that attribute because ultimately the fund owns stocks not actual diamonds. A Chicago-based firm called GemShares has filed for a physically backed diamond ETF along the lines of physically backed precious metals funds like the SPDR Gold Trust ( GLD), but there is no word yet on when or if the fund will actually list. Whereas the gold that backs GLD is stored in a vault that is about the size of a large hot tub, it's amusing to think that if a physical diamond ETF were to ever start trading, its entire asset base could fit in an envelope. Realistically, there is no effective way to capture the excesses exhibited in the art or precious stones market through exchange-traded products. If you are in the so-called 1% then you may be able to simply buy the real thing but the rest will need to wait for a more effective product to come to the market. At the time of publication, the author had GLD as a personal holding.Follow@randomrogerThis article is commentary by an independent contributor, separate from TheStreet's regular news coverage.