This stamp pictures an Amethyst, which is a type of quartz that typically appears violet due to exposure to natural low amounts of radiation. If also exposed to heat, they can be colored yellow or bright green.

A violet, crystalline variety of quartz, amethyst is the birthstone for February. When of good color and transparency, it is valued as a semiprecious gem. Such stones normally are step-cut or intaglio-carved. It occurs in cavities in many rock types and is found in the Ural Mountains, Brazil, Sri Lanka, and the United States. Ancient Greeks attributed various powers to amethyst, particularly that of protecting against drunkenness and passion.

Rhodochrosite, a mineral colored rose red. The color is due to the presence of manganese, a natural metal element that has important industrial uses. Rhodochrosite is often mined so that the manganese may be extracted.

Rhodochrosite, a manganese carbonate mineral, is a minor ore of manganese used principally as a decorative stone and gemstone. It normally has shiny, rose-red, intricately banded surfaces. Rhodochrosite occurs in moderate- to low-temperature hydrothermal ore veins, particularly of silver, lead, zinc, and copper, as well as in high-temperature metamorphic deposits.

A Tourmaline, a mineral classified as a "semi-precious gemstone". It can be found in a wide variety of colors.

Complex boron and aluminum silicate minerals, tourmalines form slender, three-, six-, or nine-sided prismatic crystals in parallel or radiating groups. Tourmalines develop an electrical charge when heated or deformed, and slabs cut perpendicular to the long axis can polarize light. The best-developed tourmaline crystals are most commonly found in pegmatite. Crystals also are found in limestone altered by granitic intrusions. Tourmaline is the birthstone for October.