Shares of Iamgold (NYSE:IAG) tumbled 6.11% in after-hours trading on Tuesday following the release of its mixed first-quarter earnings report. The gold mining company beat earnings expectations but fell short on revenue, disappointing investors.

Iamgold reported quarterly adjusted earnings of $0.10 per share, surpassing the analyst consensus estimate of $0.09 by 11.11%. However, this represents a 9.09% decrease from the $0.11 per share earned in the same period last year. The company's revenue for the quarter came in at $477.1 million, missing the analyst consensus estimate of $521.08 million by a significant 8.44%. Despite the miss, the reported revenue still marks a substantial 40.78% increase from the $338.90 million generated in the same quarter of the previous year.

The after-hours stock plunge suggests that investors are more concerned about the revenue miss than they are impressed by the earnings beat. The significant shortfall in revenue could indicate challenges in production volume or gold prices during the quarter, which may have spooked investors about the company's near-term prospects. As the market digests this mixed earnings report, all eyes will be on Iamgold's management for guidance on how they plan to address the revenue shortfall in the coming quarters.