The name (Greek) probably means “not-drunken” as amethyst was also worn an an amulet against drunkenness. Crystals are always grown onto a base. Pyramids are not well developed, therefore are often found as “crystal points” with deepest color. These crystals are broken off the base.
Heat treatment produces light yellow , green or colorless varieties (be careful when soldering) there are some amethysts that lose some color in daylight.. The original can be restored by x-ray radiation.
Found in geodes in alluvial deposits. The most important deposits are in Brazil. The best stones are faceted, others are tumbled or worked into ornaments.

*Info by Walter Schumann “Gemstones of the World”