Minerals Technologies Extends Tender Offer for Outstanding Shares of AMCOL International

NEW YORK, NY -April 18, 2014-Minerals Technologies Inc. (NYSE: MTX) announced today that it has extended its tender offer to purchase all outstanding shares of AMCOL International Corporation (NYSE: ACO) for $45.75 per share in cash. All terms and conditions of the tender offer, other than the expiration date, remain the same.

Unless extended further, the tender offer will now expire at 9:00 a.m., New York City time, on May 2, 2014. The tender offer was previously scheduled to expire at 9:00 a.m., New York City time, on April 18, 2014.

The tender offer was extended pending the expiration or early termination of the waiting period under the competition laws of Poland. Authorization by the Office of Competition and Consumer Protection in Poland is a condition to the consummation of the tender offer. On April 9, 2014, the waiting period under the Hart-Scott-Rodino Antitrust Improvements Act expired. On April 11, 2014, Minerals Technologies and AMCOL obtained clearance from the Federal Cartel Office, the German national antitrust authority. Minerals Technologies does not anticipate any regulatory concerns.

As of 12:00 a.m. midnight at the end of the day, New York City time, on April 17, 2014, approximately 23,673,893 shares had been tendered and not withdrawn, representing approximately 72.6% of AMCOL's outstanding shares of common stock. The completion of the tender offer is subject to the tender of at least a majority of AMCOL's outstanding shares of common stock (on a fully diluted basis) and other customary closing conditions, including receipt of regulatory clearances.

As promptly as practicable following the completion of the tender offer, MTI will acquire all remaining AMCOL shares through a merger at the tender offer price.

On March 21, 2014, MTI filed with the U.S. Securities and Exchange Commission ("SEC") a tender offer statement on Schedule TO which sets forth in detail the terms of the tender offer. Additionally, AMCOL has filed with the SEC a solicitation/recommendation statement on Schedule 14D-9 that includes the unanimous recommendation of AMCOL's board of directors that AMCOL stockholders accept the tender offer and tender their AMCOL shares.