# Moon rock - Page: https://taslar.bumba.tr/en/stones/moon-rock/ - Turkish: Ay kayacı - Also known as: Lunar rock, Lunar sample - Kind: Meteorite - Classification: Meteorites and impact stones › Stony meteorites - Hardness (Mohs): 5–7 - Specific gravity: 2.2–3.46 g/cm³ - Lustre: Dull, Vitreous (glassy) - Transparency: Opaque - Colours: white to transparent grey (plagioclase), maroon to black (pyroxene), greenish (olivine), black (ilmenite) - Composition: Mainly plagioclase feldspar, pyroxene, olivine and ilmenite. Highland anorthosites contain up to 90 per cent calcium-rich plagioclase; mare basalts contain 18–21 per cent FeO and 1–13 per cent TiO₂ by weight. Almost no volatiles or hydrated minerals. - Texture: Coarse-crystalline plutonic rocks and impact breccias in the highlands; volcanic basalts in the maria. Breccias range from glassy impact-melt rocks to glass-free regolith breccias. - Value ladder: 9/9 step, Museum-grade rarity Rocks brought back from the Moon: samples collected by Apollo astronauts and the Luna and Chang'e probes, telling the Moon's story over up to 4.4 billion years. Moon rock is rock that originated on the Moon. The term covers both samples collected during the exploration of the Moon and rocks ejected naturally from the Moon's surface that fell to Earth as lunar meteorites. Moon rocks on Earth come from four sources: the US Apollo programme (1969–1972), the Soviet uncrewed Luna probes (1970s), China's Chang'e missions (2020 and 2024) and lunar meteorites. This page covers the samples returned by missions. ## How does it form? Moon rocks fall into two main groups. In the **highlands** (terrae) the dominant rocks are plutonic; the most common group, the ferroan anorthosites, consists almost entirely of very calcium-rich plagioclase. These are inferred to have formed from plagioclase crystals that floated and accumulated at the top of a “magma ocean” in the Moon's early history; they are about 4.4 billion years old. The impacts that made the great basins shattered highland rocks into breccias. The **maria** consist of basaltic lavas that later filled these basins. Mare basalts come in three series according to their titanium content: high-titanium, low-titanium and very-low-titanium basalts. They are similar to terrestrial basalts but differ in important ways. Almost all lunar rocks are depleted in volatiles and completely lack the hydrated minerals common in Earth rocks; yet their oxygen isotope compositions are closely related to those of Earth rocks. ## What is it used for? - **The history of the Moon and the Solar System:** The ages of Moon rocks show when the Moon's crust formed and how long volcanism lasted. - **New minerals:** Four new minerals were discovered in lunar samples: armalcolite, tranquillityite, pyroxferroite and changesite-(Y). - **Recognising lunar meteorites:** Meteorites from the Moon are identified by comparing them with mission samples. See the [lunar meteorite](/en/stones/lunar-meteorite/) page for details. ## Samples returned by missions Six Apollo missions, whose astronauts landed on the Moon between 1969 and 1972, brought back about 2,200 samples totalling 381 kg; Apollo 17 returned the most, about 110 kg. Three Soviet Luna probes returned about 301 grams in the 1970s. China's Chang'e 5 brought back about 1,731 grams from the Ocean of Storms in 2020, in which a new mineral, changesite-(Y), was found. Chang'e 6 landed in Inner Mongolia on 25 June 2024 with the first rocks ever collected from the far side of the Moon. The main repository for the Apollo samples is the Lunar Sample Laboratory Facility at the Johnson Space Center in Houston; for safekeeping, a smaller collection is kept at the White Sands Test Facility in New Mexico. ## How to recognise it - All Moon rocks returned by missions are registered and numbered; the Apollo samples have been processed into more than 110,000 individually catalogued samples. - Anorthosites from the highlands are whitish; basalts from the maria are dark, and some are very rich in titanium because of ilmenite. - Moon rocks contain almost no volatiles or hydrated minerals, one of the features that sets them apart from Earth rocks. A firm identification requires laboratory analysis. ## What determines its value? Moon rocks collected by missions are considered priceless. According to NASA's guidebook, the Apollo samples are the property of the US government and are made available to researchers only through a controlled programme. Because they are rare and hard to replace, they have often been stolen or lost. The Moon rocks that private collectors buy and sell are lunar meteorites, which reached Earth on their own. This information is educational, not buying, selling or investment advice. Value varies enormously with quality and treatment. ## Myths and misconceptions - Myth: Moon rock and the moonstone used in jewellery are the same thing. Fact: They are not. [Moonstone](/en/stones/moonstone/) is a feldspar gemstone formed on Earth that reflects light with a bluish sheen; its name comes from its appearance. Moon rock is rock that formed on the Moon. ## Curious questions **How old are Moon rocks?** Radiometric dating gives ages from about 3.16 billion years for the basaltic samples from the maria up to about 4.44 billion years for rocks from the highlands. Crater counting suggests that the youngest basalt eruptions took place about 1.2 billion years ago, but there are no samples of these lavas. For comparison, the oldest rocks on Earth are between 3.8 and 4.28 billion years old. ## Did you know? - Armalcolite, one of four minerals discovered on the Moon, is named after the three Apollo 11 astronauts: ARMstrong, ALdrin and COLlins. - The National Air and Space Museum in Washington has a Moon rock that visitors can touch. The idea came from the Apollo scientist Farouk El-Baz, inspired by touching the Black Stone during his childhood pilgrimage to Mecca. - In 1973 President Nixon ordered fragments of Apollo 17 sample 70017 to be given to all 50 US states and 135 foreign heads of state as a goodwill gesture. Many of these goodwill Moon rocks are now unaccounted for, having been stolen or lost. ## Where is it found? - Lyndon B. Johnson Space Center, Houston, Texas, USA (Major deposit): The Lunar Sample Laboratory Facility, main repository for the Apollo Moon rocks. Most samples are kept in nitrogen to protect them from moisture and are handled only with special tools. - National Air and Space Museum, Washington, D.C., USA (Known locality): Home of the “Touch Rock”, a Moon rock that visitors may touch. ## Sources - [Moon rock](https://en.wikipedia.org/wiki/Moon_rock), Wikipedia - [Ay taşı](https://tr.wikipedia.org/wiki/Ay_ta%C5%9F%C4%B1), Vikipedi - [The density and porosity of lunar rocks (W. S. Kiefer, R. J. Macke, D. T. Britt, A. J. Irving, G. J. Consolmagno), Geophysical Research Letters 39](https://stars.library.ucf.edu/facultybib2010/2858), University of Central Florida STARS (abstract), 2012 - [Lunar Sample Allocation Guidebook](https://curator.jsc.nasa.gov/lunar/sampreq/lunarallochandbook.pdf), NASA Astromaterials Acquisition and Curation Office, Johnson Space Center - [Chang'e 6](https://en.wikipedia.org/wiki/Chang%27e_6), Wikipedia - [Handbook of Mineralogy: Anorthite](https://www.handbookofmineralogy.org/pdfs/anorthite.pdf), Mineralogical Society of America - [Handbook of Mineralogy: Augite](https://www.handbookofmineralogy.org/pdfs/augite.pdf), Mineralogical Society of America - [Handbook of Mineralogy: Ilmenite](https://www.handbookofmineralogy.org/pdfs/ilmenite.pdf), Mineralogical Society of America - [Handbook of Mineralogy: Forsterite](https://www.handbookofmineralogy.org/pdfs/forsterite.pdf), Mineralogical Society of America Source: https://taslar.bumba.tr/en/stones/moon-rock/ · Licence: CC BY-SA 4.0