Also known as igneous rocks. Under different geological conditions, rocks formed by the condensation and consolidation of molten materials from the interior of the earth. When molten magma overflows the surface of a volcano and solidifies, it is called extrusive rock or volcanic rock. Common volcanic rocks are basalt, andesite and rhyolite. When lava rises below the surface and condenses at a certain depth in the earth's crust, it is called intrusive rock, which can be divided into deep diagenesis and shallow diagenesis according to different intrusion sites. Granite, gabbro and diorite are typical plutonic rocks. Granite porphyry, gabbro porphyry and diorite porphyry are common shallow rocks. According to chemical composition, igneous rocks can be divided into ultrabasic rocks (lower than 45% SiO2 _ 2), basic rocks (45% ~ 52% SiO2 _ 2), intermediate rocks (52% ~ 65% SiO2 _ 2), acidic rocks (higher than 65% SiO _ 2) and alkaline rocks [6] (containing special alkaline mineral SiO _ 2, igneous rocks account for 64.5% of the crust volume.
The temperature and pressure inside the earth are very high, and all components (minerals) are in a molten state, which is called magmatic rocks. Igneous rocks, such as basalt and granite, are formed by magma invading the interior of the crust or flowing out of the surface to cause lava, and then cooling and solidifying. Igneous rock is the most primitive of all rocks. The primary igneous rock or sedimentary rock of metamorphic rock can change its primary rock structure or organization, or make some minerals disappear, thus becoming another kind of rock different from primary rock, called metamorphic rock, such as marble changed from limestone; Shale metamorphic slate; Quartzite changed from sandstone, etc. Typical metamorphic rocks exist in Precambrian or orogenic areas, and cleavage related to regional structure or mineral changes usually exists. There are many kinds of stones, but not all can be used. In addition to the aesthetic point of view, what is more important here is whether the chemical composition in the rock will affect the water quality, which will have a negative impact.
sedimentary rock
Also known as water rock. Layered rocks formed by transportation, deposition and diagenesis of weathered materials, pyroclastic materials, organic matter and a small amount of cosmic materials at normal temperature and pressure on the surface. Sedimentary rocks are composed of granular materials and cementing materials. Granular substances refer to cuttings and some minerals with different shapes and sizes. The main components of cementing substances are calcium carbonate, silicon oxide, iron oxide and clay. According to the genesis, it can be divided into clastic rocks, clay rocks and chemical rocks (including biochemical rocks). Common sedimentary rocks are sandstone, tuffaceous sandstone, conglomerate, clay rock, shale, limestone, dolomite, siliceous rock, iron ore, phosphorite and so on. Sedimentary rocks occupy 7.9% of the crust volume, but they are widely distributed in the surface layer of the crust, accounting for about 75% of the land area, and the seabed is almost completely covered by sediments.
Sedimentary rocks have two prominent characteristics: one is bedding, which is called bedding structure. The interface between layers is called bedding plane, and usually the rocks below are older than the rocks above. Secondly, many sedimentary rocks contain "stony" remains of ancient creatures or traces of their existence and activities-fossils, which are precious materials for judging geological age and studying ancient geographical environment, and are called "pages" and "words" for recording the history of the earth.
metamorphic rock
Rock formed by metamorphism of original rock. According to the types of metamorphism, metamorphic rocks can be divided into five categories: dynamic metamorphic rocks, contact metamorphic rocks, regional metamorphic rocks, migmatites and metasomatic metamorphic rocks. Common metamorphic rocks include mylonite, cataclastic rock, amphibole, slate, phyllite, schist, gneiss, marble, quartzite, amphibole, schist, eclogite and migmatite. Metamorphic rocks occupy 27.4% of the crust volume.
Igneous rocks, sedimentary rocks and metamorphic rocks can be transformed into each other. Igneous rocks become sedimentary rocks through sedimentation, and metamorphic rocks become metamorphic rocks through metamorphism. Metamorphic rocks can also be transformed into new sedimentary rocks, sedimentary rocks can be transformed into metamorphic rocks through metamorphism, and sedimentary rocks and metamorphic rocks can be melted and transformed into igneous rocks again. [7]
Rock has specific physical properties such as specific gravity, porosity, compressive strength, tensile strength, etc. It is a factor to be considered in construction, drilling, excavation and other projects, and also a carrier of various mineral resources. Different kinds of rocks contain different minerals. Taking igneous rocks as an example, basic ultrabasic rocks are related to iron-loving elements, such as chromium, nickel, platinum group elements, titanium, vanadium and iron. Acidic rocks are related to ishihara-loving elements, such as tungsten, tin, molybdenum, beryllium, lithium, niobium, tantalum and uranium. Diamond only occurs in kimberlite and K-Mg lamprophyre; Chromite is mostly produced in pure peridotite; The early Yanshanian granite in South China is rich in tungsten-tin deposits. Independent tin deposits and niobium, tantalum and beryllium deposits are often formed in granite in the late Yanshan period. Oil and coal exist only in sedimentary rocks. Iron ore in Precambrian metamorphic rocks is worldwide. Many stones are also important industrial raw materials, such as white marble in Beijing, which is a well-known building decoration material at home and abroad. Rainflower Stone in Nanjing, Shoushan Stone in Fujian and Qingtian Stone in Zhejiang are all good arts and crafts stones, and even river sand and pebbles that are not noticed by people are very useful building materials. Many rocks are also important raw materials of traditional Chinese medicine, such as medical stone (a kind of intermediate-acid dike rock), which is a very popular medicinal rock. Rock is also an important factor in tourism resources. The famous mountains, rivers and grottoes in the world are all related to rocks. Our ancestors have been using rocks since the Stone Age. In today's highly developed science and technology, people can't live without stones without clothing, food, shelter, transportation and medical care. Studying rocks, using rocks, hiding rocks, playing with rocks and loving rocks are no longer the patents of scientists, but gradually become an integral part of the lives of the broad masses.
fluorite
Also known as soft water amethyst, soft water green crystal and fluorite. The colors of stones are yellow, green, blue and purple. When heated, it has glass luster and fluorescence, and the crushed stone slag can be used as the filter material in the filter. In industrial production, it is often used to smelt metal fittings and make fluoride, and can also be processed into low-grade jade. Origin: Jinhua, Zhejiang, Dean, Jiangxi, Longhua, Hebei.
malachite
In fact, it is the tailings of copper mine, with green and shiny color and peacock-tail-shaped circular patterns on the stone surface, hence the name. The copper ions in it will slowly dissolve in water, which will help to supplement the demand of aquatic plants for copper, but it is not advisable to put too much or too much to prevent excessive copper.
Ross Shi Ying
Don't call it Yu Nan and Ross Timely. There are rose, light red and white. The main component is silicon dioxide. Produced in Inner Mongolia and Shanxi.
fossil wood
Also known as silicon fossils and tree fossils, 65.438+0.5 billion Jurassic trees evolved into fossils through crustal movement and volcanic ash burial before noon. There are gray, tan, brown and black. Wood fossils in the aquarium can show the vicissitudes of history more vividly. Wood fossils themselves are organic substances, which have evolved into inorganic substances over hundreds of millions of years. Their shapes still retain the outline of trees, and even the annual rings can be clearly seen from the profile, which is incomparable to any other rock. In the aquarium, green aquatic plants can represent, dead wood can represent, and wood fossils can represent ancient times. This time-honored process is fully displayed in an exaggerated way in a small aquarium. From the aesthetic point of view, aquatic plants, submerged wood and wood fossils belong to the same sex but have different materials, that is, they present a unified composition and contain changing characteristics, that is, harmony and jumping. Wood fossils are rare gems in the aquarium, which are produced in Liaoning and Zhejiang.
Black mica schist
It's mica, and black is mercerized. The main component is biotite, which is composed of claystone, siltstone or intermediate-acid volcanic rocks. Compact and exquisite structure. It is distributed all over the country.
Rush
It is composed of acidic volcanic rocks and tuff, with jade-like structure, yellow, light yellow and white. Distributed in the south of China.
Fish scale stone
Also known as tiger skin stone and pine skin stone. The colors are cyan, turquoise, yellow-red and multi-tone, with white spots and holes. Produced in Changxing, Zhejiang. It is made of limestone and should not be used in an aquarium.
Yingshi (limestone from Yingde County) is in Guangdong Province.
Gray-black to black with white or gray stripes. Named after being produced in Yingde, Guangdong, it is also called Yingde Stone.
Chrysanthemum stone
There are chrysanthemum patterns on the surface of white, gray or deep purple stones. Produced in Liuyang, Hunan.
Huxianshi
Brown, stony, is a rare stone. Produced in Huxian County, Shaanxi Province.
Turtle prolapse
Also known as wind fossils. It is made of all kinds of broken stones with mixed colors and vertical and horizontal grooves. It is mainly composed of Carboniferous rocks, in which calcium will slowly diffuse into the water, making the water quality hard. So it is not suitable for aquarium use. But it can be used in African aquatic plant landscape. Produced in Geleshan and Tushan in Chongqing, Sichuan.
Wubi stone
Also known as Qingshi. Shi Gang is very hard, so it is named for its crisp and sweet voice. There are black, white, green, brown and other colors, belonging to marble. Produced in Panshi Mountain, Lingbi County, Anhui Province.
Kunshan stone
The stone is hard, with grooves and small holes. There are yellow and white. Produced in Maanshan, Kunshan County, Jiangsu Province.
Xuan Shi
White is shiny. This stone is hard and has grooves. Produced in Xuancheng, Anhui.
Sandy schist
Also known as sand and stone. The colors of stones are gray, yellow and green. Stone is hard and can absorb water. It has grooves and holes, and it is strip or sheet. Less producing areas, mainly in western Sichuan.
Melaleuca stone
Blue-black and white flaky rocks overlap each other, and the stones are hard. Produced in Taihu Lake, Jiangsu Province.
cobblestone
There are various colors. It is produced in rivers all over the country and can be used for African-style aquatic plants landscaping.