stones divided into three parts : sedimentary . igneous and metamorphic rocks. Onyx is metamorphic rock but marble is sedimentary rock.
what is onyx?
Onyx is kind of building stone which use as a interior building such as : kitchen , bathroom , staircase, floor covering and etc...
Taj Mahal, Micheal Angeloand, New York library are build of Marble stone. this stone has coarse crystals.
How onyx geneses?
onyx is type of limestone which metamorph in high pressure and heat
onyx ingredients
the main composition of onyx is calcite crystal with purity of 99 percent . In sculpture onyx with high purity and transference are used.which is used as lightening . onyx with impure substance could change the color of onyx.
this impure substance are iron oxide , silice , mica , serpantine and graphit which could change the color of onyx into green , purple , pink , yellow , red , grey and black
specific onyx stone
water absorption: less than 1 %
specific weight : 7.2 gr into cubic cm
porosity : between 0.3 to 1.2 percent
resistance against moisture and weathering : low
resistance against scratch and erosion : low
what is marble stone?
Marble is kind of building stone which also called as a Sanandaji stone .this stone is used for flooring, paving , floors and stairs . In some cases Marble known as compact marble and sometimes find fossiles as a fossiliferous limestone.
How Marble is genesis?
Marble stone is a chemical sedimentary rock that is formed by the pressure of the upper layers and condensed of Calcite deposits into Aragonite and dolomite
this rock often form in hot water which is result of pressure of upper layers. fossils are often found in the layers of marble.during the formation of marble in addition of chemical and biochemical processes we could see a weak change of deformation.
ingredient of Marble
the main mineral of Marble is calcite and sometimes aragonite with dolomitewhich the texture is like sugar. calcite is recrystallize of calcium carbonate. the pure marble is white. but with adding of some minerals like: hematite, limonite , quartz, carbon and clay mineral it could be turns to red, green, yellow, pink, blue and ...
the various of marble stone according to geneses of other stones
according to metamorphic grades, marbles is divided into 2 groups
crystallized marble stone: this stone is formed in low metamorphic grades. the texture is fine grains
cloudy marble stone: this stone is formed in high metamorphic grades and texture is coarse grains with parallel strips
the specified of Marble stone
resistance against fire and erosion: suitable
porosity: low
water absorption: 0.31%
freezing test:accepted without any fracture
resistance against moisture and weathering : high
pushing resistance in dry condition: 1020 kg / cm3
pushing resistance in saturated condition: 980 kg / cm3
sub capacity
the main difference between marble and onyx is the genesis condition which affected the resistance
marble is high resistance to erosion and weathering which have great polishing and could be used in stairs , flooring and interior designs.
the main use of onyx is decorative stuffs and sculptures.