Hematite

Hematite is commonly seen as a silvery, shiny opaque stone that almost looks like metal. Hematite also occurs naturally in red to reddish-brown earthy masses, known as red ochre or ruddle, and in steel-gray to black crystalline forms, known as specular hematite. Hematite is heavy and a relatively hard oxide mineral because of its high iron content (about 70 percent). The most important sources of hematite come from sedimentary deposits in the Lake Superior and Birmingham district in North America. Other important locations include Minas Gerais (Brazil), Cerro Bolivar (Venezuela), Labrador, and Quebec.

Hematite derives its name from the Greek word haimatites, meaning "bloodlike," an allusion to the vivid red color of the powdered stone. The red powdered hematite, ochre (also spelled ocher), is used as a pigment with many uses presently and throughout history. Red ochre was used by prehistoric artists in their cave paintings. It was used by the ancient Egyptians in religious ceremonies, and as an inscription stone for passages in the Book of the Dead. Native Americans also used ochre as red face paint. Currently, powdered hematite is used in lapidary as a rouge polish and as a pigment in paints and crayons.

Hematite also has a history of metaphysical uses. Tribes in America used ochre as red war paint. The Roman soldiers associated this "blood stone" with Mars, the god of war. Warriors believed carrying hematite would give strength and protection to the wearer in battle. The mirror effect of polished hematite protects one from negativity by reflecting back any unwanted energy. Crystal healers credit hematite with the ability to bring about a calm mental state, improve memory and concentration, boost self-confidence, and increase the effectiveness of logical processes of the brain. Physically, hematite is believed to increase circulation, especially to the area where worn, and give all-around positive effects to the circulatory system. The astrological signs of hematite are Aries and Aquarius.

Hematite: Fe203, Iron (III) Oxide
Hardness: 5.5-6.5
Luster: metallic or dull in earthy and oolitic forms
Class: oxides and hydroxides
Color: steel or silver gray to black in some forms and red to brown in earthy forms
Transparency: opaque
Fracture: uneven to conchoidal
Crystal system: trigonal - hexagonal; bar 3 2/m
Crystal habit: include tabular crystals of varying thickness sometimes twinned, micaceous (specular), botryoidal and massive, also earthy or oolitic
Specific gravity: 4.9 - 5.3
Index of refraction: 1.54-1.55
Cleavage: absent, however, there is a parting on two planes
Streak: blood red to brownish red for earthy forms

Birthstones

Have you ever wondered what stone is associated with your birthday? Most gem scholars agree that the tradition of birthstones arose from the Breastplate of Aaron (brother of Moses): a ceremonial religious garment set with twelve gemstones that represented the twelve tribes of Israel and also corresponded with the twelve signs of the zodiac and the twelve months of the year. Because ancient people did not always classify gemstones by mineral species like we do, there is some debate about which gemstones were set in the breastplate and why. This is why different cultures around the world have developed different birthstone lists. The modern day list that you know is only the most recent list, older lists still exist. Some also argue that the proper way to assign gemstones is according to astrological sign and not month. We think it would be more fun to choose the gemstone that speaks to you from all the possibilities. That is why we have provided a chart of birthstones categorized by origin and zodiac (below).

The Modern Birthstone list is the official birthstone list from the American National Association of Jewelers, officially adopted in 1912. The Traditional Birthstone list reflects societal birthstone traditions, heralding back to the 15th century. The list contains older birthstones and is sometimes combined with the modern birthstone list; traditional lists may vary. Mystical Birthstones are of Tibetan origin and date back over a thousand years. The Ayurvedic birthstone list is from Indian medicine and beliefs dating back to ancient India (1500 BC). The Hebrew Birthstone list is one of the ancient traditional lists; others include Roman, Arabic, and Hindu. The Planetary Stone associates specific gemstones with the planets. These planets are associated with the zodiac signs, with each sign having a ruling planet. The Zodiac list below is the most agreed upon birthstone for each astrological sign. Most have several stones for each Sun sign, and depending on the reference the stones for each zodiac sign may vary.

Birthstone Chart

How to Clean Geodes

There are many different ways to clean geodes. You must be careful when using these methods not to destroy microscopic crystals. When using chemicals to clean geodes make sure you use proper protection.

CAUTION: Before doing anything, visually inspect the inside of the geode and check for microscopic minerals, for example, goethite, millerite, or kaolinite. These are very tiny and easy to overlook. Some small crystal inclusions will be damaged by scrubbing and/or chemicals. Smythite, siderite, goethite, millerite, and strontianite are a few hard-to-come-by crystals that are most times destroyed by the rockhound when cleaning the specimen with a brush and water. If the geode, when opened, has iron oxide stain (brown mud coloring), these crystals in all probability have already been destroyed.

Geology Word Puzzler

What do you call a mineral that acquires a charge when it is compressed, twisted, or distorted?

Piezoelectric crystals can generate an electric charge with the application of pressure or vibrations. By putting piezoelectric material under mechanical stress, positive and negative charges in the material move to opposite sides, which causes an external electrical field. Conversely, they can change physical dimensions with the application of an electric field. (Click here for more information.)

Quartz is the most popularly used substance of this group of minerals. Industrially, it is used for its piezoelectric properties in transducers, e.g., phonograph cartridges, microphones, and strain gauges, which produce an electrical output from a mechanical input, and in earphones and ultrasonic radiators, which produce a mechanical output from an electrical input. Other piezoelectric crystals, though less effective, include tourmaline, kyanite, labradorite, and turquoise.

We'd love to hear from you! Have questions or comments about the website, or just want to tell us about your latest rockhounding adventure? Email us at we_rock@mamasminerals.com!

Read about rose quartz, geodes, and identification of rocks and minerals in the Summer 2006 issue of RockZ NewZ

Read about fluorite, fluorescent minerals, and cleaning quartz in the Summer 2005 issue of RockZ NewZ.

Read about vanadinite, building fountains, and identifying meteorites in the Winter 2004 issue of RockZ NewZ.

Read about celestite, pearls, and how to choose the right rock tumbler in the Fall 2004 issue of RockZ NewZ.

Read about malachite, tumbling grits, and how to pan for gold in the Summer 2004 issue of RockZ NewZ.

Read about amethyst, fossil preparation, and field tools for the rockhound in the Spring 2004 issue of RockZ NewZ.

Read about galena, petrified wood, and collecting micrometeorites in the Winter 2003 issue of RockZ NewZ.

Read about iron pyrite, tumbling seaglass, and stony meteorites in the Summer 2003 issue of RockZ NewZ.

Sign up to get each new issue delivered to your inbox!