Birthstones

                                                               Birthstones

A birthstone is a gemstone that represents the month of a person's birthday. The birthstone for each month kept changing through out history and they are also diverse in different cultures, such as American, British and even Hindu. The birthstones I am going to introduce are from the U.S culture in contemporary time.

January: Garnet
A garnet is a hard and shiny stone. It is found in many colors including red, orange, yellow, green, purple, blue, and colorless, with reddish shades most common.

February: Amethyst
Amethyst occurs in colors from a light pinkish violet to a deep purple. It may also exhibit one or both secondary colors, red and blue. The color is often laid out in stripes parallel to the final faces of the crystal.

March: Aquamarine
An aquamarine is a blue variety of Beryl, appearing the color of pale blue. Its color fades to white when exposed to sunlight or is subjected to heat treatment, though the color returns with irradiation.

April: Diamond
A diamond is a transparent crystal. The most notable physical characteristics are its extreme hardness and thermal conductivity.

May: Emerald
Emerald is also a variety of Beryl, having the color of green. Their toughness (resistance to breakage) is classified as generally poor.

June: Pearl
The ideal pearl is perfectly round and smooth, but many other shapes occur. They can be dyed yellow, green, blue, brown, pink, purple, or black. The very best pearls have a metallic mirror-like luster.

July: Ruby
A ruby is a pink to blood-red colored gemstone. The brightest and most valuable "red" called blood-red or "pigeon blood."

August: Peridot
Peridot is one of the few gemstones that occur in only one color, an olive-green. The color of individual peridot gems can vary from yellow to olive to brownish-green and the most valued color is a dark olive-green.

September: Sapphire
Whilst typically associated with the color blue, natural "fancy" sapphires also occur in yellow, purple, orange, and green colors. Sapphire also has a remarkable hardness.

October: Opal
Opal is the national gemstone of Australia. The internal structure of precious opal makes it diffract light, making the color varies in a wild range. Of these hues, the black opals are the most rare.

November: Topaz
Pure topaz is colorless and transparent but is usually tinted by impurities; typical topaz is wine red, yellow, pale gray, reddish-orange, or blue brown.

December: Turquoise
Turquoise is an opaque, blue-to-green mineral. It is rare and valuable in finer grades and has been prized as a gem and ornamental stone for thousands of years owing to its unique hue.

References:

 Kunz, George F. (1913). The curious lore of precious stones. Lippincott. pp. 275–306.

 Grande, Lance; Augustyn, Allison (2009). Gems and Gemstones: Timeless Natural Beauty of the Mineral World. University of Chicago Press. p. 335. 

 Knuth, Bruce G. (2007). Gems in Myth, Legend and Lore (Revised edition). Parachute: Jewelers Press. p. 294.