Limestone is a sedimentary rock composed largely of minerals calcite and aragonite which are different crystal forms of calcium carbonate
Limestone is made by precipitation of calcite dissolved in water and by deposition of marine organisms
Limestone is found in Egypt, Moroco, Israel, Canada, Croatia,France, Germany, Australia , New Zealand.
Limestone is yoused in crop fertilization also yoused for a portion of the Great Wall of China ,toothpaste ,food supplement as asourse of calsiom,certain cosmetics
Limestone is being used in toothpaste
Quartzite is a rock composed of firmly cemented Quartz grains most quartzite are metaphorphic but also exist sedementery quartzite.
Quartzite is made when Quartz-rich sandstone or chert has been exposed to high temperature and pressure.
Canada,Brazil,Germany,Madagascar,China,South Africa,and Venezuela.
Quartzite used in phones
Obsidian is formed in the larges stage of volcanic eruption the silicas left over.
How it's formed
Formed by rapid cooling of viscous.
Where it's found
It is yoused in knifes,arrowheads,spear points,scrapers and othe weapons and tools