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Kimberlites are not only the most economically important source of diamonds; they also carry unique information encapsulated in rock fragments entrained as the magma traverses the whole thickness of the lithosphere. The Nurbinskaya pipe in the Siberian kimberlite province (Russia) is one of several intruded along the Vilyui Rift, a major terrane boundary. The pipe contains three populations of mantle-derived zircon xenocrysts: Archean (mean age 2709 ± 9 Ma), Devonian (mean age 371 ± 2.3 Ma), and a subset of grains with evidence of brittle deformation and rehealing, and a range of ages between 370 and 450 Ma. The Hf-isotope, O-isotope and trace-element signatures of the last group provide a link between the Archean and Devonian events, indicating at least three episodes of magmatic activity and zircon crystallization in the lithosphere beneath the pipe. The emplacement of the Nurbinskaya pipe ca 370 Ma ago was only the youngest activity in a magma plumbing system that has been periodically reactivated over at least 2.7 billion years, controlled by the lithosphere-scale structure of the Vilyui Rift.

He+ ion implantation at 4.0 MeV, equivalent to energy of α particles from natural radioactive nuclei 238U and 232Th, has been conducted for undoped synthetic zircon. The cathodoluminescence (CL) of implanted samples was measured to clarify the radiation-induced effects. Unimplanted synthetic zircon shows pronounced and multiple blue emission bands between 310 nm and 380 nm, whereas the implanted samples have an intense yellow band at ~550 nm. The blue emission bands can be assigned to intrinsic defect centers formed during crystal growth. The yellow band should be derived from induced-defect centers by He+ ion implantation, which might be related to the metamicitization originated from a self-induced radiation in natural zircon. The yellow band may be separated into two emission components at 1.96 eV and 2.16 eV. The emission component at 2.16 eV is recognized in both unimplanted and implanted samples, and its intensity increases with an increase in the implantation dose. The CL of zircon can be used as the geodosimeter.

Cryptoperthitic alkali feldspars in the Cerro Colorado monzonites from the Atacama Desert, northern Chile, exhibit bluish iridescence. Three types of cryptoperthites are developed over a grain; fine and coarse cryptoperthites of Or-Ab-An ternary compositions around Or 60–65 Ab 35–30 An 5 , and Or-rich, An-poor cryptoperthite around Or 70 Ab 26 An 4 . The former ternary compositions point to crystallization at approximately 900°C. Hydrothermally turbid patch microperthites are not developed in the alkali feldspar, whereas turbid Or-rich veins with micropores display limited replacement of the cryptoperthites along the lamellae. The Or-rich veins are much richer in water than the cryptoperthitic regions. Blue cathodoluminescence of variable tint is observed over individual grains, except in the Or-rich veins. The Cerro Colorado alkali feldspars record an incipient state of alkali feldspars, which predates the low-temperature formation of patch microperthite in subsolvus granites. These feldspars are the first natural alkali feldspars with K-feldspathization without microperthite formation.