What is the screen made of?
The Apple iPhone 6's screen is made out of Potassium which is an Alkali metal on the Periodic Table of elements that helps to strengthen the glass. It is also composed of the compounds Al2O3 (Aluminium oxide) and SiO2 Silica or Silicon Dioxide).
In order to make the glass function as a touch screen three elements are needed: Indium, Tin and Oxygen. Indium Oxide (In2O3) and Tin Oxide (SnO) are combined it make Indium Tin oxide which then get put into the glass film where it conducts electricity and operates the touch screen.
Apple Touch Screen in use
Are these materials hazardous?
Tin and Indium oxide are hazardous materials. As like all hazardous materials, they have special disposal methods. Otherwise, it could have serious effects. This website talks about Tin and Indium oxide and the effects it could have ecologically. http://www.espimetals.com/index.php/msds/588-Indium-Tin%20Oxide
Where can these elements be found?
Indium has a number of interesting properties. For example, it has a low melting point for metals, 156.6°C. When pure, it sticks very tightly to itself or to other metals. This makes it useful as a solder. Solder is a material used to merge two metals to each other. Other uses of indium are in the manufacture of batteries, electronic devices, and in research.
Tin does not occur as the native element but must be extracted from various ores. Tin is found mainly in the ore Cassiterite, which is found in Malaysia, Bolivia, Indonesia, Thailand and Nigeria. It is obtained by reducing the ore with coal in a reverberatory furnace.
Usage rates and growth markets
Consumption of indium grew at an ever-increasing rate from 1990 to 2005 because of its notable use in indium tin oxide (ITO) stimulated demand. Growth slowed a little from 2005 to 2008 and the industry was badly hit by the global downturn in 2009. Market essentials began to improve in early 2010.