This article is part of a 20 article special report on "Metals, miners and money".

The SPDR S&P Metals & Mining (AMEX: XME), "a play on hard assets, has delivered impressive gains of 52% over the past 12 months," notes Paul Tracy who has added the ETF to the Sector Trading Portfolio of The ETF Authority.

The advisor explains, "While investors shouldn't grow accustomed to red-hot annual gains of 50%, this ETF is an ideal way to gain exposure to this sector." Here is his review.

"XME has been in the right place at the right time. The ETF mirrors the S&P Metals & Mining and invests in hard assets like precious metals (gold), industrial metals (copper, aluminum), steel, and coal.

"According to studies conducted by research firm Ibbotson, this group has a very low correlation with other traditional asset classes, and a modest stake can boost long-term returns with negligible additional risk -- and that has certainly been the case lately.

Launched on July 30th, Claymore/Robb Report Global Luxury (NYSE: ROB) is an exchange-traded fund that, according to Paul Trach, targets the upper crust of the consumer discretionary sector.

The editor of The ETF Authority notes that the fund is designed to track the performance of the world's premium luxury companies, with a portfolio that looks like a who's who of luxury brands.

The specialty index tracked by the fund, he notes, was constructed by Robb Media, which manages a number of publications aimed at the ultra-affluent. Tracy says, "Robb has its finger on the pulse of the world's wealthiest individuals."

He explains, "The portfolio contains about 40 holdings that read like a who's who of upscale brand names: Coach (NYSE: COH), Polo Ralph Lauren (NYSE: PL), Saks (NYSE: SKS), Sotheby's (NYSE: BID), Tiffany (NYSE: TIF), and Wynn Resorts (NYSE: WYNN), among others.

And with stakes in countries like France, Switzerland, Italy, and Germany and holdings in such companies as Hermes, Porsche, and Harry Winston, he notes, "ROB offers global exposure to some of the world's most iconic companies."