What do toothpaste, household batteries, some medicines, coins, and the steel beams in buildings all have in common? They each contain minerals that come directly from the earth.
A mineral is a solid formed by natural geological processes which usually work very slowly, sometimes over millions of years. Because each mineral species always has the same chemical and internal structure, its physical and visual properties are consistent, too. For example, every sample of beryllium silicate (better known as an emerald) will have the same hardness and density, regardless of its geographic location upon discovery.
All minerals (ranging from the commonly found quartz to rarely found gold) are finite resources. Once they are mined, they are essentially gone forever. It will take millions of years for natural geological processes to replenish them.
Meteorites are chunks of solid rock from outer space that strike Earth. Along with rocks collected during expeditions to the moon, meteorites are the only physical evidence scientists have of matter created in the distant reaches of the cosmos.
Meteorites are classified by their mineral composition and texture and are named for the places where they are found. They may contain minerals found on Earth plus other minerals that are only known to exist elsewhere in the universe.
The Academy has 150 meteorites in its collection. They are categorized by three basic types: first, iron; second, stony meteorites—judged to be one of the oldest rocks in the universe; and third, rare stony-iron meteorites that are mixtures of iron, nickel, and silicate materials.
Gems and carvings are usually cut from high quality mineral specimens that generally have few occlusions or impurities. The Academy’s gem collection complements its mineral collection. Displayed together, natural and cut specimens of a given species show how familiar gems are related to the raw materials from which they are made.
Transparent stones are usually cut into faceted gems while opaque or translucent materials are formed into cabochons, beads, or carvings. The shape of a worked gemstone often reflects the mineral’s underlying crystalline structure. For example, long prismatic crystals of tourmaline or topaz are often cut into rectangular or oval gems.
Coral reefs, the most diverse and productive marine habitat on Earth, support an immense variety of animals, from sponges and nudibranchs to carnivorous fishes and corals. But today, destructive fishing practices, pollution, and rising ocean temperatures are destroying these vital communities, spurring international efforts to protect them.
Before conservation measures can be taken, however, scientists must have a clear picture of reef ecology. Academy scientists, including curators Dr. Gary Williams and Dr. Terry Gosliner, have visited many reefs to assess their health and biodiversity. One of the most important areas is the “High Diversity Triangle,” an area formed by the Philippines, Papua New Guinea, and Indonesia, known to have the highest diversity of marine life in the world. Williams and Gosliner have discovered new species of invertebrates and established new records of others. In some areas, they found that a common fishing practice—using dynamite to stun fish—not only killed corals, but also depleted reefs of other forms of life.
Using this region and others as models, researchers hope to find patterns of diversity that indicate whether a reef is healthy or sick. Their results will be vital to global conservation efforts.