Amethyst - February Birth Stone

Amethyst is derived from the Greek "amethustos" meaning not drunk. It is though to protect against drunkenness, as well as to protect soldiers from harm in battle.

Hardness/Toughness	Specific Gravity	Refractive Index
H-6.5-7, T-Good	2.66	1.544-1.533

Aquamarine - March Birth Stone

Aquamarine is a symbol of youth and happiness, derived from the Latin for "sea-water" because of its blue/green color. It is though to promote power over evil and produce increased understanding. It was also thought to treat certain illnesses with the lungs and eyes.

Hardness/Toughness	Specific Gravity	Refractive Index
H-7.5-8, T-Fair	2.67-2.84	1.577-1.583

Blue Topaz - November Birth Stone

Topaz is derived from Topazion the name of an Island in the Red Sea where yellow stones (probably peridot) were found. Topaz then became a generic name for any yellow stone. It is most plentiful in yellow naturally, but when irradiated and heated it turns to shades of blue. It was thought to protect against evil and was used to treat many different ailments including asthma.

Hardness/Toughness	Specific Gravity	Refractive Index
H-8, T-Poor	3.53	1.619-1.627

Blue Zircon - December Birth Stone

Zircon comes from the Arabic "zircon" meaning orange-red colored. Naturally it is found in this color; however, the stone is now treated with heat to turn a light blue color that is now most popular. It was thought to induce sleep, prevent disease, thwart evil and bring good fortune to those who posses it.

Hardness/Toughness	Specific Gravity	Refractive Index
H-6-6.5, T-Poor	3.93-4.73	1.810-1.984

Citron

Citrine, like Amethyst, is part of the quartz family. Citrine meaning yellow is from the Latin "citrus" for citrus tree. Due to its durability this is the preferred stone when a yellow color is called for.

Hardness/Toughness	Specific Gravity	Refractive Index
H-7, T-Good	2.66	1.544-1.553

Diamond - April Birth Stone

Coming from the Greek "Adamas" meaning invincible. Although diamonds may be forever, they just recently were discovered by women. Prior to the 19th century diamond were only worn by men who thought they promoted bravery and strength in battle.

Hardness/Toughness	Specific Gravity	Refractive Index
H-10, T-Good	3.52	2417

For more on diamonds see our Diamond Information Guide

Emerald - May Birth Stone

Coming from the same mineral as aquamarine, beryl, emeralds range in color from light to dark green and also blue/green hues. It has been used to treat eye problems and improve memory.

Hardness/Toughness	Specific Gravity	Refractive Index
H-7.5-8, T-Poor	2.67-2.84	1.577-1.583

Garnet - January Birth Stone

Garnet is derived from the Latin "granatus" meaning "seed like" due to its similar appearance to the pomegranate seed. Although garnet appears in many different colors, the most widely found is red. Due to its red color it is associated with blood, and thus was thought to stop bleeding or bloodshed between enemies.

Hardness/Toughness	Specific Gravity	Refractive Index
H-6.5-7.5, T-Fair	3.30-4.18	1.72-1.875

Green Tourmaline

The stone takes its name from the Ceyolese word "turamali" meaning parcel of precious jewels. Although tourmaline comes in a rainbow of colors the most popular at this time are green and pink. The green strain is also know as "chrome", "indicolite" is the name for blue shades.

Hardness/Toughness	Specific Gravity	Refractive Index
H-7-7.5, T-Fair	3.01-3.21	1.624-1.644

Opal - October Birth Stone

The name Opal is derived for the Latin "opallus" for "precious stone". It is generally divided into two groups, white and dark, but both share the similar appearance where a spectrum of colors can be seen in the depths of the stone. Ancients believed that the stone might protect you from disease or give you the power of seeing the future.

Hardness/Toughness	Specific Gravity	Refractive Index
H-5.5-6.5, T-Poor	1.25-2.22	1.45

Pearl - June Birth Stone (or Moonstone/Alexandrite)

The Pearl is one of the only gemstones that is produced by a living creature. Although once plentiful in nature, most pearls now are cultured by man. This still involves the oyster doing its part but man inserts a nucleus into the oyster to spur the production of a pearl.

Hardness/Toughness	Specific Gravity	Refractive Index
H-3-4, T-Good	2.60-2.78	1.52-1.66

For more on Pearls see our Pearl Information Guide

Peridot - August Birth Stone

The name Peridot was coined by the French, but the root is from the Arabic word "faridat" meaning "gem". Due to its yellow green color it was know as the "gem of the sun".

Hardness/Toughness	Specific Gravity	Refractive Index
H-6.5-7, T-Poor	3.31-3.48	1.654-1.690

Pink Tourmaline

The stone takes its name from the Ceyolese word "turamali" meaning parcel of precious jewels. Although tourmaline comes in a rainbow of colors the most popular at this time are green and pink. Pink is considered an alternative for opal as October's birthstone. The pink to red color of tourmaline is also called "rubellite".

Hardness/Toughness	Specific Gravity	Refractive Index
H-7-7.5, T-Fair	3.01-3.21	1.624-1.644

Ruby - July Birth Stone

Derived from the Latin "ruber" meaning "red", the ruby was thought to aid in romantic pursuits. It was also thought to bring the wearer vitality, wealth and wisdom.

Hardness/Toughness	Specific Gravity	Refractive Index
H-9, T-Good	4.00	1.762-1.770

Sapphire - September Birth Stone

Sapphire, like Ruby, is a member of the corundum family. The name sapphire is derived from the Hebrew and Persian word for blue. Although it is most prevalent in blue, sapphire comes in green, yellow, orange, pink and purple. It was thought to be a symbol of truth and faithfulness.

Hardness/Toughness	Specific Gravity	Refractive Index
H-9, T-Good	4.00	1.762-1.770

Turquoise

Turquoise like opal is opaque, reflecting light from small transparent layers within the stone. The name is derived from the French meaning Turkey which is where the stones were originally imported from. Its color can range from blue-green and light-blue to yellowish-green.

Hardness/Toughness	Specific Gravity	Refractive Index
H-5.6, T-Fair	2.60-2.80	1.61-1.65