Gold has been recognized and highly-valued since prehistoric times. It might have been the first metal used by humans and was valued for both ornamentation and rituals. Gold is the most malleable and ductile metal; a single gram could be beaten into a sheet of one square meter, or an ounce into 300 square feet. Gold leaf can be flattened thin enough to become translucent. The transmitted light appears greenish blue, as gold strongly reflects yellow and red. It readily forms alloys with many other metals. Gold is an excellent conductor of heat and electricity, and is not affected by air and most reagents. Heat, oxygen, moisture, and most corrosive agents have very little chemical effect on gold, making it very well-suited for use in coins and jewelry. Pure gold is so soft for ordinary use and is hardened by alloying with copper or other base metals. The gold content of gold alloys is measured in carats (k), pure gold being designated as 24k.

Butterflies are adult flying stage of certain insects belonging to an order or group called Lepidoptera. Moths also belong to this group. The word "Lepidoptera" means "scaly wings" in Greek. This name completely suits the insects in this group because their wings are covered with thousands of tiny scales overlapping in rows. The scales, which are arranged in colorful designs unique to every species, are what give the butterfly its beauty. Like all other insects, butterflies also have six legs and three main body parts: head, thorax (chest or mid section) and abdomen (tail end). They also have two antennae and an exoskeleton.

Hurricane Katrina was the one of the five deadliest hurricanes in the history of the United States. It was the sixth-strongest Atlantic hurricane that was ever recorded and the third-strongest hurricane on record that made landfall in the United States. Katrina formed on August 23 during the 2005 Atlantic hurricane season and caused devastation along the north-central Gulf Coast. The most severe loss of life and property damage occurred in New Orleans, Louisiana, which flooded as the levee system catastrophically failed; in many cases hours after the storm had moved inland. In the 2005 Atlantic season, Katrina was the eleventh tropical storm, fifth hurricane, third major hurricane, and second Category 5 hurricane.

An earthquake is caused by sudden, violent shifting of massive rocks called plates lying under the earth's surface. This movement of the plates releases stress that accumulates along geologic faults. A fault is a deep crack that marks the boundary between two of the plates. Earthquake belts occur along faults all around the world. Many run along coastal areas. The San Andreas Fault in central California is well-known for causing most severe earthquakes. The epicenter is the point on the surface where the earthquake is strongest. The Richter scale is used to measure the amount of energy that is released by the earthquake.

A teacup is a small cup with a handle, generally a small one that may be grasped with the thumb and one or two fingers. It is normally made of porcelain. It is usually part of a set, composed of a cup and a matching bowl. These in turn may be part of a tea set in combination with a teapot, cream jug, covered sugar bowl and slop bowl en suite.

Some collectors attain numerous one-of-a-kind cups with matching saucers. Better teacups normally are of fine white lucid porcelain and often decorated with floral patterns. They may also observe a location, person, or event. Such collectors may also accumulate silver teaspoons. These usually have a decorated terracotta insert in the handle with similar themes.

The first small cups specifically made for drinking the new potion tea seen in Europe were exported from the Japanese port of Imari. Tea bowls in the Far East did not have handles, and the first European imitations, made at Meissen, were without handles, too.

Birds (class Aves) are bipedal, warm-blooded, vertebrate animals that lay eggs. There are around 10,000 living species, making them the most abundant tetrapod vertebrates. They populate ecosystems across the globe, from the Arctic to the Antarctic. Birds range in size from the 5 cm (2 in) Bee Hummingbird to the 2.7 m (9 ft) Ostrich. The fossil record indicates that birds evolved from theropod dinosaurs during the Jurassic period, around 150–200 Ma (million years ago), and the earliest known bird is the Late Jurassic Archaeopteryx, c 155–150 Ma.

Modern birds are characterised by feathers, a beak with no teeth, the laying of hard-shelled eggs, a high metabolic rate, a four-chambered heart, and a trivial but strong skeleton. All birds have forelimbs modified as wings and most can fly, with some exceptions including ratites, penguins, and a number of diverse endemic island species. Birds also have unique digestive and respiratory systems that are highly adapted for flight. Some birds, especially corvids and parrots, are among the most intellectual animal species; a number of bird species have been observed manufacturing and using tools, and many social species exhibit cultural program of knowledge across generations.

Many species undertake long distance annual migrations, and many more perform shorter asymmetrical movements. Birds are social; they communicate using visual signals and through calls and songs, and participate in social behaviours including cooperative breeding and hunting, flocking, and mobbing of predators. The vast majority of bird species are socially monogamous, usually for one breeding season at a time, sometimes for years, but rarely for life. Other species have breeding systems that are polygynous ("many females") or, rarely, polyandrous ("many males"). Eggs are usually laid in a nest and incubated by the parents. Most birds have an extended period of parental care after hatching.

Many species are of economic importance, mostly as sources of food acquired through hunting or farming. Some species, particularly songbirds and parrots, are popular as pets. Other uses include the harvesting of guano (droppings) for use as a fertiliser. Birds figure prominently in all aspects of human culture from religion to poetry to popular music. About 120–130 species have become destroyed as a result of human activity since the 17th century, and hundreds more before then. Currently about 1,200 species of birds are threatened with extinction by human activities, though efforts are underway to protect them.

Large wild cat found in Africa and Asia. The background colour of the fur is golden, and the black spots form rosettes that differ according to the mixture; black panthers are simply a colour distinction and retain the patterning as a ‘watered-silk’ effect. The leopard is 1.5–2.5 m/5–8 ft long, including the tail, which may measure 1 m/3 ft. (Species Panthera pardus, family Felidae.)

The snow leopard or ounce (Panthera uncia), which has irregular rosettes of much larger black spots on a light cream or grey background, is a native of mountains in central Asia. The clouded leopard (Neofelis nebulosa) is rather smaller, about 1.75 m/5.8 ft overall, with large blotchy markings rather than rosettes, and is found in Southeast Asia. There are seven species, of which six are in danger of extinction, including the Amur leopard and the South Arabian leopard. One subspecies, the Zanzibar leopard, may already be extinct. The last Judean desert leopard died May 1995, although a small population survives in the Negev Desert.