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See here for some ideas. You may want to do some testing, at least for Mohs hardness. But comparing your samples to the typical pictures shown in the referenced site I would guess an alkali feldspar (hardness = 6) or perhaps rose quartz (hardness =7). Note the hardnesses, a steel file falls in between at 6.5.


Weren't all the natural radioactive isotopes created during the formation of the solar system? The half life of carbon 14 is 5730 years, orders of magnitude less than the age of the solar system. Carbon 14 is constantly being created in the upper atmosphere by neutron bombardment of nitrogen 14. On the other hand, the other isotopes used in radioactive ...


Chile has sedimentary deposits (gravels) about 12 Ma, in Atacama desert.


Radioactive dating works on specific isotopes we use for specific time frames. Rubidium–strontium dating methods (because this substance has a half life of 50 billion years) to date extremely old geological samples as well as space samples like lunar rocks. Another issue is the quantity of synthetic isotopes in varying samples. Alot of these isotopes do not ...


There are other, mostly chemical processes which alter the isotope ratios. Isotope dating uses a combination of them. This is why it can not be used always, for any radioactive isotopes, only in special circumstances. It also requires very sensitive measurements (below in the second example, close to induvidually count lead atoms in microscopic zircon ...

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