Amethyst and calcite geode from the Los Catalanes district, ready for sale. Credit: Fiorella Arduin Rode The amethyst geodes, of rare beauty, form in volcanic rock cavities. How did these purple ...

Commissions do not affect our editors' opinions or evaluations. Large-cap companies—those with market caps larger than $10 billion and up to more than $1 trillion—are usually companies with ...

Having a big, but still pocketable, smartphone gives me lots of screen space to enjoy video or games on, and a large battery to keep enjoying them on while I'm out away from a charger. And if you ...