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.