Facebook (NASDAQ: FB) CEO Mark Zuckerberg has done it again. Zuckerberg has donated liberally to a charity in Silicon Valley to address health and education issues.

Zuckerberg has parted with 18 million Facebook shares valued at $498.8 million based on the Dec. 18 closing price, the Associated Press has reported.

Silicon Valley Community Foundation is the recipient. A not-for-profit organization, the charity helps donors identify and manage charitable funds in sync with their philanthropic passions. And the current charity donation is identified to be Zuckerberg's biggest donation to date.

Besides, it also appears to be the biggest donation made by Facebook after its IPO in May 2012. Prior to the IPO, Zuckerberg pledged $100 million in Facebook shares to Newark and New Jersey public schools in 2010.

This apart, in 2010, Zuckerberg and his wife Priscilla Chan joined the Giving Pledge initiative led by Microsoft Corp. (NASDAQ:MSFT) founder Bill Gates and Berkshire Hathaway Inc. (NYSE:BRK/A) CEO Warren Buffett that urges all the rich donors to part with their wealth.

In a Facebook posting Tuesday, Zuckerberg noted how he and his wife donated 18 million Facebook shares to the Foundation, adding: "Together, we will look for areas in education and health to focus on next. I'm hopeful we'll be able to have as positive an impact in our next set of projects."

Appreciating Zuckerberg's generous gesture, Emmett D. Carson, chief executive office of the foundation, stated: "Mark's generous gift will change lives and inspire others in Silicon Valley and around the globe to give back and make the world a better place."

Reminiscing with pride the work done with Startup: Education in Newark, Zuckerberg wrote on the Facebook post: "I'm really proud of the work we've done there, helping leaders like Governor Chris Christie and Mayor Corey Booker sign the most progressive teachers contract in our country, opening four new district high schools, 11 new charter schools and more."

Shares of Facebook rose 4 cents to $27.45 in Thursday trading.