The official rock of Tennessee is limestone. The raccoon is the state’s official wild animal.

But the state still does not have an official book.

Republican Gov. Bill Haslam last week vetoed a bill that would have added the Bible to Tennessee’s list of official state symbols, but lawmakers have already threatened to override his decision.

In Haslam’s veto message to the Republican lawmakers who sponsored the bill, he wrote in defense of Christian beliefs: “I strongly disagree with those who are trying to drive religion out of the public square.”

However, Haslam said, there’s the matter of constitutional law — separation of church and state.

“If we are recognizing the Bible as a sacred text, then we are violating the Constitution of the United States and the Constitution of the State of Tennessee by designating it as the official book,” Haslam wrote. “Our founders recognized that when the church and state were combined, it was the church that suffered in the long run.”

Haslam’s veto came a little more than a week after Idaho Republican Gov. C.L. “Butch” Otter vetoed a bill that would have allowed the Bible to be used in public schools for instruction, also citing constitutional concerns.

In Tennessee, all it takes to override a veto are majority votes in both chambers of the Legislature, and the bill’s two Republican sponsors have already signaled their intent to go around the governor.

Eighty-one percent of Tennessee’s adults are Christians, according to the Pew Research Center, and the state is familiar with battles over church and state. It was home to the legendary 1925 Scopes trial of a teacher on charges of illegally teaching evolution in school. He was convicted.

The Bible bill was introduced last year but stalled in the Legislature. The attorney general issued an opinion saying it would be unconstitutional.

The bill reemerged this March and was approved 55-38 in the House and 19-8 in the Senate.

A series of “whereas” statements extols the Bible’s importance to the state, as in “whereas, printing the Bible is a multimillion-dollar industry for the state with many top Bible publishers headquartered in Nashville, including Thomas Nelson, Gideons International and United Methodist Publishing House.”

Conservative religious groups such as the Family Action Council of Tennessee supported the bill. “If the state cannot recognize its religious heritage without supposedly violating the Constitution, then our heritage will be lost and hostility toward religion will have replaced tolerance,” President David Fowler said in a statement.

The bill’s opposition was based on spiritual grounds as well as constitutional ones. Haslam said that if the book is embraced as a cultural item rather than as a holy one, “my personal feeling is that this bill trivializes the Bible.”

The American Civil Liberties Union of Tennessee also objected. “Our position has always been that religion thrives when it’s left in the hands of families and faith communities,” said executive director Hedy Weinberg.