Although there is not a specific rock that is magnetic, certain magnetic properties of a rock may be found in the crystals and minerals that make up a rock. The magnetic mineral magnetite is commonly found in igneous roc... More »

Lodestone is a magnetic mineral that is found in igneous and metamorphic rocks. It is a type of magnetite, which are minerals that possess a strong attraction to magnets. More »

Magnetic disks tend to come in two varieties: the hard metal platters inside hard drives and the more flexible magnetic platters inside floppy disks. As of 2014, most hard drives use either 3.5- or 2.5-inch platters, whi... More »

Solid iodine consists of shiny bluish-black crystals, but iodine vapors are a purple gas. Iodine is named after the appearance of the iodine vapors, as "iodes" is the Greek word for purple. More »

Survivalists and outdoorsmen add iodine crystals to water, because iodine chemically purifies and disinfects untreated water. These crystals are used as a temporary measure, as iodine can be toxic in large quantities, es... More »

The compound with the chemical formula CuSO4 x 5H2O is called copper (II) sulfate pentahydrate, and it appears in the form of blue crystals, granules or powder. Also referred to as blue vitriol, copper sulfate pentahydra... More »

Magnesium sulfate crystals can be prepared from Epsom salt available in pharmacies. Natural magnesium sulfate exists as the mineral kieserite, MgSO4?H2O, which is purified by crystallization. More » Science Chemistry