You may be thinking of "[Dune Roller][1]" (1951) by [Julian May][2]. [Here is a page][3] containing some information about the story, as well as links to various radio and video adaptations. The story can also be accessed [here][4], but only the first few pages are available for free.

The story is set in a remote town on the shore of Lake Michigan. Here's a synopsis as I recall it:

The story opens sometime in prehistory, when a meteor appears and explodes over the lake. A fish eats one of the fragments and dies.

The story proper introduces a scientist who is studying the local wildlife. While inspecting an inlet he finds a strange, bright-colored, smooth stone with a little pointy section like a tail. Later, some kids find a dead frog and bring it to him. He autopsies the frog and finds it died from internal injuries. He also finds another of these stones in its stomach. The scientist bribes the kids to find more stones, and he eventually ends up with half a dozen samples. 

The scientist visits a friend who works at a glass factory. The friend thinks the stones might be something like a [Prince Rupert's drop][5].
While hammering on one of his samples (as one might do with a Prince Rupert's drop), he discovers that the stone can emit great amounts of heat.

Other strange things are happening in the community. I think some residents are found burned to death, with strange tracks leading into the water.

>! As the story progresses, the scientist figures out that the stones can
>! move by rolling around, and they can coalesce into larger stones. One of the
>! locals was seemingly killed by a stone the size of an ostrich egg.

</br>

>! The scientist develops the theory that there's a bigger stone out there
>! somewhere. In the climax, the scientist sets a dynamite trap on the beach and
>! uses his samples to draw in the large stone. A truly massive Dune
>! Roller appears out of the water and ends up being blown to bits.

</br>

>! In an epilogue, the story describes two little grains of sand on the
>! beach, which seem to glow slightly, and then merge together. The
>! cycle begins again...


  [1]: http://www.isfdb.org/cgi-bin/title.cgi?56099
  [2]: https://en.wikipedia.org/wiki/Julian_May
  [3]: http://www.sffaudio.com/dune-roller-by-julian-may/
  [4]: https://www.scribd.com/document/141664230/Julian-May-Dune-Roller
  [5]: https://en.wikipedia.org/wiki/Prince_Rupert's_Drop