25 april 2018 9:56 am edt add It is extremely unlikely that radiation from granite countertops 9:59 am edt add Radon originating from the soil beneath homes is a more common problem 10:30 am edt add my granite counter top has 2 tiny cracks, i don't know how that happen. 10:53 am edt 1. reword my granite counter top has 2 tiny cracks, i don't know how that happen. to our granite counter top has 2 tiny superficial cracks, i don't know how that happen. 2. reword diamond tip saw-blade to diamond tipped saw-blade 9 may 2018 2:10 am edt move to http://wortel.ucoz.com/granit.htm using format like https://gamefaqs.gamespot.com/snes/588646-secret-of-mana/faqs/5611 ;; dark granite (melfic), is denser/stronger than bright granite (felsic). source : 1. dark = mafic bright = felsic in http://facweb.bhc.edu/academics/science/harwoodr/Geol101/labs/igneous/CIndex.htm 2. 'mafic rocks are also high in density and dark in color', 'Felsic rocks are generally light in color and lower in density than mafic rocks' in http://regentsearth.com/Illustrated%20ESRT/Page%206%20%28Igneous%29/Mafic-Felsic.htm from google 'mafic vs felsic' bright granite is more radioactive than dark granite. source : 'Some granites contain around 10 to 20 parts per million (ppm) of uranium. By contrast, more mafic rocks, such as tonalite, gabbro and diorite, have 1 to 5 ppm uranium' in https://en.wikipedia.org/wiki/Granite 'Granite, like any other stone, may contain veins of naturally occurring radioactive elements like uranium, thorium, and their radioactive decay products. These trace concentrations may vary from stone to stone, or even within a single slab of granite. If present, uranium, thorium or radium will decay into radon, a colorless, odorless, radioactive gas that may cause lung cancer. Radon released from granite building materials can be released over the lifetime of use but typically will be diluted by ventilation. In addition to radon, naturally occurring radioactive elements in the granite can emit small amounts of beta and gamma radiation. However, any radiation present would decrease quickly with increasing distance from the source. It is extremely unlikely that radiation from granite countertops would increase annual radiation doses above normal, natural background levels.', 'Radon originating from the soil beneath homes is a more common problem and a far larger public health risk than radon from granite building materials.' in https://www.epa.gov/radiation/granite-countertops-and-radiation from google (granite radioactivity ppm) result 2 dark granite names : gabbro, basalt, scoria bright granite names : granite pegmatite, granite, rhyolite source : http://facweb.bhc.edu/academics/science/harwoodr/Geol101/labs/igneous/ dark granite, hides food stain, then removing that dried food stain can be difficult, may cause damage to the granite. our granite counter top has 2 tiny superficial cracks, i don't know how that happen. i thought only diamond tipped saw-blade can damage granite because granite is very hard, i don't have diamond tipped saw-blade.