Most were photographed prior to collection to record the condition in which they were found.
They were placed inside sample bags and then a Special Environmental Sample Container for return to the Earth to protect them from contamination.
ANSMET), with most of the remainder having been discovered by collectors in the desert regions of northern Africa and Oman.
Why is radiometric dating important 66 dating com
A combined total of less than one kilogram of material was returned.
In 1993, three small fragments from Luna 16, weighing 200 mg, were sold for US$ 442,500.
They consist of quartz, plagioclase, orthoclase or alkali feldspar, rare mafics (pyroxene), and rare zircon.
The alkali feldspar may have unusual compositions unlike any terrestrial feldspar, and they are often Ba-rich.
They range in age from about 3.16 billion years old for the basaltic samples derived from the lunar maria, up to about 4.44 billion years old for rocks derived from the highlands.
Moon rocks fall into two main categories: those found in the lunar highlands (terrae), and those in the maria.These rocks apparently form by the extreme fractional crystallization of magnesian suite or alkali suite magmas, although liquid immiscibility may also play a role.U-Pb date of zircons from these rocks and from lunar soils have ages of 4.1-4.4 Ga, more or less the same as the magnesian suite and alkali suite rocks. O'Keefe and others linked lunar granites with tektites found on Earth although many researchers refuted these claims.An interesting aspect of this suite is that analysis of the trace element content of plagioclase and pyroxene require equilibrium with a KREEP-rich magma, despite the refractory major element contents.The alkali suite is so-called because of its high alkali content—for moon rocks.In some regards, lunar rocks are closely related to Earth's rocks in their isotopic composition of the element oxygen.