I keep an eye out but this is actually this first carved stone book I've found, and definitely meant to represent a bible, with sacred heart in high relief across the front. There is a finely carved border around the perimeter on both front and back as well as three rows of three lines on the spine, and what I assume are the initials of the carver, AD, at the bottom left corner of the heart, which kicks a bit in the that direction! I believe the super smooth pink stone is soapstone and would guess it dates to the first quarter of the 20th century or so; these became an American  folk art genre around 1870, reaching the height of popularity around the turn of the century I believe.

4 3/16" x 2 11/16" x 1 1/8". There is a small chip and repair to the bottom right corner of the back side and a repaired diagonal crack running from the top of the spine to the back top left edge, both as detailed in photos and neither visible from the front. There is a fine, dark line running diagonally on the front to the right of the heart, which is indigenous to the stone and in the stone itself, the surface there is smooth.