stone is a rock or synthetic properties equivalent to the rock as raw materials processed into materials, including marble, granite, slate, sand and so on. The status of stone in the decorative materials is very high, and it has irreplaceable decoration, which can show the noble temperament of the building.
This article selects some common stone nouns, and briefly shares the main types and characteristics of stone for every stone person and friends who are interested in stone.
1.
Magmatic rocks: rocks formed by the condensation of magma, also called igneous rocks.
Sedimentary rock: A rock formed by the consolidation of sediments.
metamorphic rock: the original rock formed after metamorphism.
Granite: Deep acid magmatic rock composed mainly of quartz, feldspar, mica and a few other dark minerals.
Limestone: Sedimentary rock composed primarily of calcite.
Marble: Metamorphic rock with carbonate minerals (mainly calcite and dolomite) greater than 50%.
2. stone
now commonly used stone types are divided into four categories: sedimentary rocks, metamorphic rocks, igneous rocks and artificial stone.
1. Sedimentary Rock
sedimentary rocks are separated from debris from organisms such as glaciers, rivers, wind, oceans and plants, deposited to form rock deposits, and consolidated by high temperature and high pressure for millions of years.
(1) Limestone: The main mineral composition is calcite. Mineral particles and crystal structure are rare, the surface is smooth, small granular. The hardness is different, some dense limestone can be polished.
(2) Sandstone: formed by quartz particles, stable structure, usually light brown or red, mainly containing silicon, calcium, clay and iron oxide.
(3) Soapstone: It is formed by various talc and is very soft. It is a wear-resistant dense ore, not easy to produce stains.
(4) Fossils: Natural fossils containing marine shellfish and plants, considered to be limestone.
(5) Travertine (Kongshi): generally cream or reddish, formed by the deposition of calcite from hot springs.
2. Metamorphic rock
metamorphic rocks are naturally metamorphosed from one stone to another under the mixing action of high temperature, high pressure and minerals. The qualitative change may be recrystallization, texture or color change.
(1) Marble: It is recrystallized limestone. The limestone becomes soft under high temperature and high pressure, and recrystallizes to form marble when the minerals contained therein change. The main components are calcium and dolomite, many colors, usually have obvious patterns, many mineral particles.
(2) Slate: Metamorphic rock formed from claystone, sedimentary shale (sometimes quartzite), with fine mineral particles, thin and friable, usually black, gray or green.
(3) Serpentine: It is named for its pattern like snakeskin, and the most common colors are green and brown. The Mohs hardness is between 2.5 and 4. It contains a large amount of magnesium and is derived from igneous rocks.
3. igneous rock
igneous rocks are mainly formed by volcanic materials, such as magma, so they are also called magmatic rocks. After the liquid magma under the surface cools and solidifies, mineral gases and liquids penetrate into the rock to form new crystals and various colors.
granite: mainly composed of quartz (35%), feldspar (45%) and potassium formation, generally dark color. Calcite is very small even if it is contained. The texture is very hard and easier to maintain than marble, but there are still small holes and stains. According to the mixing ratio of quartz, mica and feldspar, granite is divided into different types.
4, artificial stone
artificial stone is made of non-natural mixtures, such as resin, cement and gravel adhesive.
(1) terrazzo: Marble and granite fragments embedded in cement mixture.
(2) Condensation stone or aggregate stone: Marble chips are embedded in a colored resin mixture.
(3) culture stone or imitation stone: resin mixture on the paint or mixed with paint, looks like marble.
Several Characteristics of 3. Natural Stone
1. Fire resistance
all kinds of stone are different, some stone under the action of high temperature, chemical decomposition. Gypsum is decomposed at more than 107 ℃, limestone and marble are decomposed at more than 910 ℃, and granite is cracked due to uneven heating of constituent minerals at 600 ℃.
2. Expansion and contraction
stone also expands with heat and contracts with cold, but if it is cooled after being heated, its contraction cannot be restored to its original volume, and a part of it must be retained to become permanent expansion.
3, freezing resistance
stone in the wet state, can resist freezing and thawing without significant damage, this performance is called frost resistance. The water in the rock pores freezes when the temperature is as low as minus 20 ℃, and the water in the pores expands 1/10 larger than the original volume. If the rock cannot resist the force caused by this expansion, it will be destroyed. Generally, if the water absorption rate is less than 0.5, its frost resistance is not considered.
4. Compressive strength
stone will be different due to factors such as mineral composition, crystal thickness, uniformity of cemented material, load area, load effect and cleavage angle. If other conditions are the same, usually the crystal particles are small and bonded to each other, the dense material has a higher strength. After the dense volcanic rock is dry and saturated with water, there is no difference in compressive strength (very low water absorption). If it is porous and water-afraid cemented rock, its dry and wet strength is significantly different.
