Investors interested in Basic Materials stocks should always be looking to find the best-performing companies in the group. Rio Tinto (RIO) is a stock that can certainly grab the attention of many investors, but do its recent returns compare favorably to the sector as a whole? One simple way to answer this question is to take a look at the year-to-date performance of RIO and the rest of the Basic Materials group's stocks.Rio Tinto is a member of our Basic Materials group, which includes 239 different companies and currently sits at #6 in the Zacks Sector Rank. The Zacks Sector Rank includes 16 different groups and is listed in order from best to worst in terms of the average Zacks Rank of the individual companies within each of these sectors.The Zacks Rank is a proven system that emphasizes earnings estimates and estimate revisions, highlighting a variety of stocks that are displaying the right characteristics to beat the market over the next one to three months. RIO is currently sporting a Zacks Rank of #1 (Strong Buy).Over the past 90 days, the Zacks Consensus Estimate for RIO's full-year earnings has moved 47.64% higher. This signals that analyst sentiment is improving and the stock's earnings outlook is more positive.Based on the latest available data, RIO has gained about 6.74% so far this year. Meanwhile, the Basic Materials sector has returned an average of 5.25% on a year-to-date basis. This means that Rio Tinto is performing better than its sector in terms of year-to-date returns.Looking more specifically, RIO belongs to the Mining - Miscellaneous industry, a group that includes 45 individual stocks and currently sits at #110 in the Zacks Industry Rank. On average, this group has gained an average of 6.59% so far this year, meaning that RIO is performing better in terms of year-to-date returns.Investors with an interest in Basic Materials stocks should continue to track RIO. The stock will be looking to continue its solid performance.Want the latest recommendations from Zacks Investment Research? Today, you can download 7 Best Stocks for the Next 30 Days. Click to get this free report Rio Tinto PLC (RIO): Free Stock Analysis Report To read this article on Zacks.com click here.