Identifying Major StoneTypes

This information was taken from The Association of Gravestone Studies. It has been very helpful to me so I though I would share it.


GRANITE

• Igneous rock with visible grain, primarily quartz and feldspar
• Speckled appearance with sparkly mica and dull black flecks
• Extremely hard rock that is difficult to carve by hand
• Grays, pinks in a wide range of colors
• Commercial granites include gneiss and other rocks not strictly granite
• Exhibits a full range of grain sizes with uniform surface patterns
• Granular with no discernable bedding planes
• Often used for monuments and tombs

LIMESTONE

• Soft, sedimentary rock primarily composed of calcite
• Fossils may be recognizable and are the most diagnostic trait
• Tan, buff or gray colored that darkens with age
• Matte surface almost never polished
• Somewhat rough texture, rarely “sugars” like marble
• No marked veining like marble
• No definite layers or bedding planes like sandstone
• No sparkly mica grains like granite
• Often gets gypsum crusts

MARBLE

• Hard, dense crystalline or granular metamorphic limestone
• White when new or in new breaks, but older marbles may appear gray from soiling
• Capable of taking a high polish, yellows with age
• May have veins of gray or gold
• Commercial marble is any lime carbonate capable of taking a polish, could include limestone and many colors
• Tennessee marble is medium-grained similar to limestone in texture with a pink cast
• Georgia marble is very large-grained, somewhat gray in color
• Predominant stone for gravestones in the 19th century
• Many early marbles are eroded and “sugaring”

SANDSTONE

• Sedimentary rock composed of cemented sand grains – “bedding planes”
• Red and brown (Brownstone) in color, can be gray, tan or blue (Bluestone)
• Fine-grained stone with sand grains
• Often flakes and delaminates

· SLATE

• Metamorphosed shale, hard and brittle
• Usually black, gray or blue
• Sometimes fades with time
• Extremely smooth, fine-grained stone with even bedding planes usually running parallel with the stone’s face
• Holds carving very well, inscriptions usually very clear
• Uniform surface appearance
• Gravestones tend to be thin and simple in shape, generally not more than six inches

SOAPSTONE

• Metamorphic rock
• Largely composed of the mineral talc and is rich in magnesium
• Easily carved and darkens over age
• Smooth to the touch
• Used in 19th century, commonly for slot and tab tombs in Georgia
• White, gray, greenish gray, pale green -- commonly discolored in reddish or brownish hues and mottled