Teen SF novel: boy finds a time-traveling pebble/pearl, realizes that every change made to time distorts his life more and more

Question

Searching for a time travel novel I read when I was a teenager in middle school, circa 1995, about a kid or young man who finds some kind of a marble or pebble or pearl or something that gives him the ability to travel through time.

My recollection of the whole thing is very vague. If I remember correctly, he uses the object more and more excessively throughout the novel and sort of like what happens in that movie "The Butterfly Effect" with Ashton Kutcher, he gradually realizes that each time he travels back in time and changes something he ends up just screwing things up more and more until his life just about completely falls apart.

Answer 1

The book you're describing is likely The Green Futures of Tycho (1981) by William Sleator. From Amazon:

When eleven-year-old Tycho discovers that the mysterious egg-shaped object he dug up in his garden is a time travel device, he can’t resist using his newfound power. Soon he is jumping back and forth in time, mostly to play tricks on his bossy older brothers and sister. But every time he uses the device, he notices that things are different when he gets back—and the futures he visits are getting darker and scarier. Then Tycho comes face-to-face with the most terrible thing of all: his grown-up self. Can Tycho prevent the terrible future he sees from coming true?