Facts about Natural Stone
Natural stone is an investment that will give you many
years of beautiful service. Stone is a natural product and simple care and
maintenance will keep it looking beautiful.
Granite, marble and other natural stone are natural
occurring materials. Each type of stone is unique and will vary in color,
texture, and marking. Color, vein, and shade variances, fissure cracks, and
pits are normal characteristics of natural stone.
It is important you are aware of the following facts
about natural stone.
No two slabs of granite or
marble or other natural stone will be the same; therefore variation in color
and texture are normal and expected. Some colors are more uniform than
others; however, even in a uniform color large black spots, a vein, or an
off color mark are still possible. These naturally occurring variances can
not be avoided when cutting. Top of page.
Granite and marble have
seams where two slabs are joined together. Seams are visible to the eye and
noticeable to the touch. There may be a noticeable difference in color and
texture where two slabs are seamed. Seams on veined or patterned materials
will not match. The fabricator has absolute design decision on the number
and location of seams. The number and location of seams is based on the
amount of material available, size of material, cutouts, manageability of
pieces, room layout and installation considerations.
When using under mount
sinks and cook tops the fabricator will not deviate from the factory
specifications for the cutout. Each under mount sink has a different reveal
and you should be aware of how the reveal will look before selecting your
sink. All items needed for cutouts or drillings must be selected prior to
fabrication. Cook tops and sinks must be on the job site the day of
installation. Top of page.
A polished finish on
the stone has a glossy surface that reflects light and emphasizes the color
and marking of the material.
A honed finish is a
satin smooth surface with relatively little light reflection.
Top of page.
Information From the
Many common foods and
drinks contain acids that will etch, stain or dull the surface of many
stones. It is recommended you use coasters under all glasses. You should not
place hot items directly on the stone surface. Use trivets or mats under hot
dishes and placemats under china, ceramics, silver or other objects that can
scratch the surface. Top of page.
Cleaning Procedures and Recommendations
Natural stone can be
classified into two categories according to its composition: a siliceous
stone or calcareous stone. Knowing the difference is critical when selecting
Know Your Stone
Siliceous stone is
composed mainly of silica or quartz-like particles. It tends to be very
durable and relatively easy to clean with mild acidic cleaning
solutions. Types of siliceous stone include granite, slate, sandstone,
quartzite, brownstone and bluestone.
Calcareous stone is
composed mainly of calcium carbonate. It is sensitive to acidic cleaning
products and frequently requires different cleaning procedures than
siliceous stone. Types of calcareous stone include marble, travertine,
limestone and onyx.
Clean stone surfaces with
stone soap (available at hardware stores) or mild liquid dishwashing
detergent and warm water. Use a soft cloth for best results. Do not use
products that contain lemon, vinegar, or other acids on marble or other
calcareous stones. Rinse the surface thoroughly after washing with the soap
solution and dry with a soft cloth. Do not use scouring powders or creams;
these products contain abrasives that may scratch the stone.
Top of page.
Certain products can stain
natural stone, especially light colored material and porous stone like
marble. Blot the spill with a paper towel immediately. Do not wipe the area,
this could spread the spill. Flush the area with plain water and mild soap
and rinse several times. Dry the area thoroughly with a soft cloth. Repeat
as necessary. Top of page.
Surface stains can often be
removed by cleaning with an appropriate cleaning product or household
chemical. Deep-seated or stubborn stains may require using a poultice.
(grease, tar, cooking oil, milk, cosmetics)
An oil-based stain will
darken the stone and normally must be chemically dissolved so the source of
the stain can be flushed or rinsed away. Clean gently with a soft, liquid
cleanser that contains bleach OR ammonia OR mineral spirits OR acetone.
DO NOT MIX AMMONIA AND BLEACH. THIS COMBINATION CREATES A TOXIC AND
LETHAL GAS. KR2 upholstery cleaner can also be
used (found at Eckerd's).
tea, fruit, tobacco, paper, food, leaves, bark)
May cause a pinkish-brown
stain and may disappear after the source of the stain has been removed from
the surface. Clean with 12% hydrogen peroxide (hair bleaching strength) and
a few drops of ammonia.
Metal (iron, rust, copper, bronze)
Metal stains must be
removed using a poultice. (See section on making a poultice) Deep-seated,
rusty stains are extremely difficult to remove and the stone may be
markers, pen ink)
Clean with bleach or
hydrogen peroxide (light colored stone only) or lacquer thinner or acetone
(dark stones only). Top of page.
Making and Using a Poultice
A poultice is a liquid cleaner or chemical mixed
with a white absorbent material to form a paste about the consistency of
peanut butter. The poultice is spread over the stained area to a thickness
of about ¼” to ½” with a wood or plastic spatula, covered with plastic and
left to work for 24 to 48 hours. The liquid cleaner or chemical will draw
out the stain into the absorbent material. Poultice procedures may have to
be repeated to thoroughly remove a stain, but some stains may never be
Poultice materials include kaolin, fuller’s
earth, whiting, diatomaceous earth, powdered chalk, white molding plaster or
talc. Approximately one pound of prepared poultice material will cover one
square foot. Do not use whiting or iron-type clays such as fuller’s earth
with acid chemicals. The reaction will cancel the effect of the poultice. A
poultice can also be prepared using white cotton balls, white paper towels,
or gauze pads.
Cleaning Agents or Chemicals
Oil-based Stains: Poultice
with baking soda and water OR one of the powdered poultice materials and
Organic Stains: Poultice with
one of the powdered poultice materials and 12% hydrogen peroxide
solution OR use acetone instead of the hydrogen peroxide.
Iron Stains: Poultice with
diatomaceous earth and a commercially available rust remover. Rust
stains are particularly difficult to remove.
Copper Stains: Poultice with
one of the powdered poultice materials and ammonia. Copper stains are
particularly difficult to remove.
Biological Stains: Poultice
with one of the poultice materials and dilute ammonia OR bleach OR
hydrogen peroxide. DO NOT MIX AMMONIA AND BLEACH. THIS COMBINATION
CREATES A TOXIC AND LETHAL GAS.
Top of page.
Applying the Poultice
the poultice. If using powder mix the cleaning agent or chemical to a thick
paste the consistency of peanut butter. If using paper, soak in the chemical
and let drain. Do not let the liquid drip.
the stained area with distilled water.
the poultice to the stained are about ¼” to ½” thick and extend the poultice
beyond the stained area by about one inch.
the poultice with plastic and tape the edges to seal shut.
the poultice to dry thoroughly, usually 24-48 hours. The drying process is
what pulls the stain out of the stone and into the poultice material. After
about 24 hours remove the plastic and allow the poultice to dry.
the poultice from the stain; rinse with distilled water and buff dry with a
the poultice application if the stain is not removed. It may take up to five
applications for difficult stains.
Top of page.
Granites and marbles are quarried throughout the world in a variety of colors
with varying mineral compositions. In most cases, marbles and granites can be
identified by visible particles at the surface of the stone.
will normally show "veins" or high concentrations of minerals.
The minerals in Granite will typically appear as small flecks
distributed uniformly in the stone.
Each type of stone is unique and will vary in color, texture and marking.
Sandstones vary widely in color due to different minerals and clays
found in the stone. Sandstone is light gray to yellow or red. A dark reddish
brown sandstone, called Brownstone, has commonly been used in the
northeastern United States and eastern Canada. Bluestone is a dense,
hard, time-grained sandstone of greenish-gray or bluish gray color and is
quarried in the eastern United States.
Limestone is a widely used building stone with colors typically light
gray, tan or buff. A distinguishing characteristic of many limestones is the
presence of fossils that are frequently visible in the stone surface.
is a dark green, black, gray, dark red or multi-colored. It is
most commonly used as a flooring material and for roof tiles and is often
distinguished by its distinct by its distinct cleft texture.
Top of page.