Discover Insights About Crystals and Minerals

Calcite fizzes in acid because it releases carbon dioxide. Dolomite only fizzes when powdered. How geologists use the acid test, and the prison story behind dolomite.

Vivianite forms where phosphate from bones meets iron in waterlogged ground. Real cases: an 1861 iron coffin, a 1963 plane crash crew, Seven Years War soldiers, and Otzi.

Long Island beaches hold real garnet and magnetite sand, slightly radioactive monazite at Montauk, and glacier-carried stones from New England. Where to look and why.

The oldest known piece of Earth is a zircon crystal from Australia, about 4.4 billion years old and only twice the width of a hair. How it was dated, and what it revealed.

Tanzanite comes from one 7 km strip in Tanzania. Reserve estimates, the 24 km mine wall, record finds, and why “gone in 20 years” claims keep circulating.

Most Ethiopian Welo opal is hydrophane: it soaks up water, can turn clear, and recovers as it dries. What actually happens, how to care for it, and the opal on Mars.

Flint forms inside chalk because dissolved sponge skeletons re-harden as silica, often filling ancient burrows. Plus paramoudras and Poland’s striped-flint mines.

Your inner ear runs on calcite crystals, your teeth are apatite, and kidney stones are named minerals. A geology tour of the real crystals inside the human body.

Bismuth crystals grow in minutes, lab quartz in weeks, and the giant Naica gypsum crystals about a billionth of a meter per day. Real measured crystal growth rates.

Bismuth is technically radioactive: its only natural isotope decays with a half-life about a billion times the age of the universe. Here is what that means for your bismuth crystal.