Not necessarily. Intrusive igneous rocks, especially pegmatites, can have large crystals.
Both plutons and pegmatites are formed from the slow cooling of molten rock beneath the Earth's surface. This slow cooling allows for the formation of large mineral crystals. Additionally, both plutons and pegmatites can contain a variety of minerals, often including rare or uncommon ones due to the unique conditions of their formation.
Crystal size in these rock types is determined by their rate of cooling. Pegmatites have large crystals due to very slow cooling. Obsidian has microscopic crystals due to almost instantaneous cooling.
Pegmatite rocks can contain some of the largest crystals found in nature, sometimes reaching several meters in length. These crystals are often visually striking due to their size and clarity, making pegmatites popular among mineral collectors and geologists.
They are associated with the late stages of granite intrusions and the minerals formed in pegmatites literally had the time to enjoy the benefits of a slow crystallization process from a rich chemical stew produced by the cooling granite.
slow cooling of gaseous magma
Not necessarily. Intrusive igneous rocks, especially pegmatites, can have large crystals.
Veins of extremely coarse-grained igneous rocks are referred to as pegmatites. These veins are formed from the last minerals to crystallize in a cooling magma, resulting in very large crystals. Pegmatites can contain economically valuable minerals such as lithium, beryllium, and rare earth elements.
Veins of extremely coarse-grained igneous rocks are called pegmatites. These veins form from the crystallization of mineral-rich magma, resulting in very large crystals due to slow cooling and high water content. Pegmatites are commonly found in association with granitic rocks.
They are associated with the late stages of granite intrusions and the minerals formed in pegmatites literally had the time to enjoy the benefits of a slow crystallization process from a rich chemical stew produced by the cooling granite. For an alternate hypothesis, see the link below.
Very large silicate mineral grains (crystals) indicate extremely fast, in-melt transport of the mineral constituents to the growing crystals. We know that pegmatite magmas are small volume, relatively low temperature melts that are extremely rich in water and other dissolved volatiles. The volatiles promote very fast rates of material transfer, thus accounting for rapid growth of very large crystals.
Ore deposits are often associated with hydrothermal processes, where minerals are deposited from hot fluids circulating in the Earth's crust. Gem crystals are often found in igneous and metamorphic rocks, where the conditions for their formation are present, such as high pressure and temperature.
A pegmatite is an intrusive igneous rock comprised of coarse, interlocking mineral grains usually above three centimeters in diameter. Although very many pegmatites are granitic in composition, several hundred mineral species have been found in the most famous pegmatites worldwide, including many rare and valuable minerals. A few discovered pegmatite crystals have grown to several meters across.
These deposits are likely pegmatites, which are igneous rocks with exceptionally large crystals. Pegmatites can host rare minerals and ores due to their unique formation process, which involves late-stage crystallization of magma enriched in rare elements like lithium and beryllium. These deposits are important sources for these rare metals and are often mined for their economic value.
Both plutons and pegmatites are formed from the slow cooling of molten rock beneath the Earth's surface. This slow cooling allows for the formation of large mineral crystals. Additionally, both plutons and pegmatites can contain a variety of minerals, often including rare or uncommon ones due to the unique conditions of their formation.
Pegmatites are coarse-grained igneous rocks that often contain gem-quality crystals of minerals such as beryl and tourmaline. They also have high concentrations of relatively rare elements like lithium, boron, and beryllium due to their unique mineral composition and formation process in the Earth's crust.
i think the answer is pegmatites or something... i just googled it myself your corect it is pegmatites