Hi all. I just came across this interesting tidbit. If you want to keep your headstones "age appropriate" to your theme, check out this list of how a headstones age is determined by what they're made from.
DATING GRAVESTONES
If your ancestor has a stone made of slate or common fieldstone (except wood used by pioneers), chances are the stone dates from 1796-1830.
If the stone is flat-topped hard marble, dates are about 1830-1849.
If the "mystery" stone is round or pointed soft marble with cursive inscriptions, look for a date of 1845-1868.
Masonic four-sided stones began in 1850 and are still in use today.
Pylons, columns and all exotic-style monuments are usually dated 1860-1900.
Zinc monuments date from 1870-1900.
Granite, now common, came into use about 1900.
I got this from here>>>>>>>>>>>>>>>>>>>>>>>>>
http://www.ghostseekers.com/Gravestones.htm