By Jon Swartz, San Francisco, Cal. (USA TODAY) -- Facebook CEO Mark Zuckerberg is definitely in the holiday-giving mood.
Late Tuesday, he donated 18 million of his shares in the social-networking company -- worth nearly $500 million -- to the non-profit Silicon Valley Community Foundation, which works in education and health initiatives.
"I'm hopeful we'll be able to have as positive an impact in our next set of projects," Zuckerberg said in a status update on his Facebook page.
It's Zuckerberg's second big donation since he joined the Giving Pledge, the Bill Gates-Warren Buffett organization that has asked the wealthiest people in the U.S. to give to worthwhile causes. Other notable tech leaders who have contributed include Netflix CEO Reed Hastings, AOL co-founder Steve Case and Microsoft co-founder Paul Allen.
His first centered on education reform with Startup: Education in Newark, N.J.
"I'm really proud of the work we've done there, helping leaders like (New Jersey) Gov. Chris Christie and (Newark) Mayor Cory Booker sign the most progressive teachers contract in our country, opening four new district high schools, 11 new charter schools and more," Zuckerberg wrote on his Facebook profile.
Zuckerberg's donation capped a hectic day for Facebook.
Instagram said that was not the intent of the update, which it said was misinterpreted.