DIOROTE of Puma Punku
Article in Progress by Pat Darnell and Saul Buck
It was known since antiquity for its hardness and was used for building by the Maya and the Inca in foundations, and by Islamic architects too, as material for pavements. Due to its hardness, it was used to create intricate artifacts. The Egyptians used it to fashion granite due to its very hardness.
It is extremely rare to come by and is found in the Andes mountains, Sondrio in Italy, Thuringia and Sassonia in Germany, Scotland, the Isle of Guernsey, Minnesota USA, Sweden and Romania.
Quality of the stonework, and immense size of the stones makes this ruin very puzzling. Details in the stonework are hardly possible achievable tolerances in today's stone carving.
Equally interesting is how the Inca empire was only 100 years old when it sucumbed to Pizarro and his boys. Short and sweet. (SOURCE)
Personally, this is the first time I have looked at a surface that comes to us from out of antiquity and said to myself: That is not possible. Stone specifications for wall construction have a "flatness factor" that must be kept a small number. These stone slabs are as flat as if this was polished with a twenty step coarseness grinder\sander. I am truly baffled.
Dolomite might have been agood stone to work with in ancient times, but guess what? These stones are igneous formed Diorite, a kind of granite or gabbro...
Granite is a coarse-grained rock found in plutons—large, deep-seated bodies of rock that slowly cooled from the molten state. Thus it is the typical plutonic rock. Granite is thought to form as hot fluids from deeper in the mantle rise and trigger widespread melting in the continental crust. This gallery shows some of the variety of granites.
Diorite is a plutonic rock that is something between a granite and a gabbro. It consists mostly of white plagioclase feldspar and black hornblende.
Hardness: Hardness (as measured with the Mohs scale) actually refers to minerals rather than rocks, so a rock may be crumbly yet consist of hard minerals. But in simple terms, "hard" rock scratches glass and steel, usually signifying the minerals quartz or feldspar (Mohs hardness 6-7 and up); "soft" rock does not scratch a steel knife but scratches fingernails (Mohs 3-5.5); "very soft" rock does not scratch fingernails (Mohs 1-2). Igneous rocks are always hard.Part Two: Why is the difference between Dolomite and Diorite?
A granitoid meets two criteria: (1) it is a plutonic rock that (2) has between 20 percent and 60 percent quartz.
A worldwide average of the average proportion of the different chemical components in granites, in descending order by weight percent, is:
The chemical compound 'silicon dioxide', also known as 'silica' , is an oxide of silicon with a chemical formula of and has been known for its hardness since antiquity....
Aluminium oxide is an amphoteric oxide of aluminium with the chemical formula 23. It is also commonly referred to as alumina or aloxite in the mining, ceramic and materials science communities....
Potassium oxide is a Chemical compound of potassium and oxygen. This pale yellow solid, the simplest oxide of potassium, is a rarely encountered, highly reactive species....
Sodium oxide is a chemical compound with the formula Sodium2Oxygen. It is used in ceramics and glasses. Treatment with water affords sodium hydroxide....
Calcium oxide , commonly known as burnt lime, Lime or quicklime, is a widely used chemical compound. It is a white, Caustic and alkaline crystalline solid at room temperature....
Iron oxide, also known as ferrous oxide, iron oxide/oxidized iron or more commonly rusted iron, is one of the iron oxides. It is a black-colored powder with the chemical formula ....
Iron oxide?also known as ferric oxide, Hematite, red iron oxide, synthetic maghemite, colcothar, or simply rust?is one of the several oxide Chemical compounds of iron, and has Paramagnetism properties....
Magnesium oxide, or magnesia, is a white solid mineral that occurs naturally as periclase and is a source of magnesium . It has an empirical formula of ....
Titanium dioxide, also known as titanium oxide or titania, is the naturally occurring oxide of titanium, chemical formula titaniumoxygen2....
Phosphorus pentoxide is a chemical compound with formula Phosphorus2Oxygen5. This white crystalline solid is the anhydride of phosphoric acid....
Manganese oxide is the chemical compound with formula MnO. It occurs in nature as the rare mineral manganosite.Preparation and chemistry...
Based on 2485 analyses
Plagioclase tends to be more transparent than alkali feldspar; it also very commonly shows striations on its cleavage faces that are caused by multiple crystal twinning within grains. These appear as the lines in this polished specimen.
One way is to determine the mineral's density by putting crushed grains in immersion oils of different densities. (Albite's specific gravity is 2.62, anorthite's is 2.74, and the others fall in between.) The really precise way is to use thin sections under the petrographic microscope, determining the optical properties along the different crystallographic axes.
The amateur has a harder time. Large grains of plagioclase like this specimen display two good cleavages that are off square at 94° (plagioclase means "slanted breakage" in scientific Latin). The play of light in these large grains is also distinctive, resulting from optical interference inside the mineral.
A noteworthy occurrence of this unusual rock type makes up the heart of New York's Adirondack Mountains (see the next page of this gallery); another one is the Moon. This specimen, a gravestone, is an example of anorthosite with less than 10 percent dark minerals.
Granite has been intruded into the crustCrust (geology)
of the EarthEarth
during all geologic periods, although much of it is of PrecambrianPrecambrian
The Precambrian is an informal name for the supereon comprising the eon of the geologic timescale that came before the current Phanerozoic eon....
age. Granitic rock is widely distributed throughout the continental crustContinental crust
of the Earth and is the most abundant basement rockBasement rock
Basement rock usually refers to the thick foundation of ancient, and oldest metamorphic and igneous rock that forms the Crust of continents, often in the form of granite....
that underlies the relatively thin sedimentarySedimentary rock
Sedimentary rock is one of the three main Rock types . Sedimentary rock is formed by deposition and consolidation of mineral and organic material and from precipitation of minerals from solution....
veneer of the continents.
Despite being fairly common throughout the world, certain areas are well known for their commercial granite quarries:
[Article to be proofed and drawn corrected at later date]
Next Week: Popular MAR's -- Sedimentary, Igneous, Metamorphic