Consumers frequently encounter a deep, metallic, silver-gray material sold in jewelry stores and online as “hematite.” This popular substance is frequently marketed for its strong magnetic properties, which is the source of significant confusion for consumers. Natural hematite is an iron-bearing mineral, but its inherent physical properties do not include the powerful magnetism displayed by the retail product. The discrepancy arises because the term “magnetic hematite” is a commercial label applied to a manufactured material that only mimics the appearance of the natural stone. This article examines the scientific differences between the mineral hematite and its magnetic counterpart.
The Science of True Hematite
Genuine hematite is a naturally occurring mineral composed of ferric iron oxide (\(\text{Fe}_2\text{O}_3\)). It is one of the most abundant iron oxides on the planet. Its name is derived from the Greek word for blood, referencing the distinct red color of its powdered form. Hematite crystallizes in a rhombohedral structure, which dictates how the iron atoms are arranged within the material.
The arrangement of atoms in pure hematite results in a specific magnetic behavior known as antiferromagnetism at room temperature. In this state, the magnetic moments of the iron atoms are aligned in opposite directions, effectively canceling each other out. This atomic structure means that pure, natural hematite is virtually non-magnetic, and it will not strongly attract a common refrigerator magnet.
Any slight magnetic attraction sometimes observed in natural hematite specimens is due to the presence of an impurity. Hematite often forms alongside another iron oxide mineral called magnetite, which is strongly magnetic. When a natural sample of hematite contains small embedded traces of magnetite, it can exhibit a weak pull toward a magnet, but it will never possess the strong attraction of the retail product.
The most definitive test for natural hematite is the streak test, which involves rubbing the mineral across an unglazed ceramic plate. Regardless of whether the sample appears silver, black, or reddish-brown, true hematite will always leave a reddish-brown streak. The mineral is also quite dense, possessing a specific gravity of around 5.3, meaning it feels heavier than many other stones of a similar size.
The Composition of Manufactured Magnetic Material
The material widely sold as “magnetic hematite,” “Hematine,” or “Hemalyke” is not a naturally occurring mineral but a synthetic ceramic composite. This manufactured substance is engineered specifically to be strongly magnetic while visually resembling polished, natural hematite. It is classified chemically as a ferrite, a type of ceramic compound containing iron oxide combined with other metallic elements.
The composition of this magnetic material involves mixing iron oxide with elements such as barium or strontium to create a strong, permanent magnet. This mixture is processed, heated, and then shaped into beads or pendants, which are the common forms seen in jewelry. The resulting material is a type of ceramic magnet that is artificially magnetized to exhibit ferromagnetism, meaning it has a powerful, enduring magnetic field.
Unlike the natural mineral, this synthetic material can be easily shaped into uniform, flawless pieces, which makes it ideal for mass-produced jewelry. Some manufacturing processes involve creating a composite from powdered natural hematite and magnetite, which is then pressed and permanently magnetized in a strong electromagnetic field. This process ensures the material is reliably and strongly magnetic.
The strong attraction of this manufactured ferrite is what allows “magnetic hematite” jewelry to form clasps that snap together or for multiple beads to stick to one another. Essentially, the product is a functional magnet that has been colored and polished to mimic the look of the natural mineral. This manufactured composite offers a consistent, strong magnetic property that the natural mineral cannot provide.
Identifying Genuine Hematite vs. the Magnetic Counterpart
Distinguishing between the natural mineral and the manufactured magnetic composite is straightforward using a few simple methods. The most immediate test is to use a common household magnet, such as one from a refrigerator. The synthetic material will exhibit a powerful attraction, often strong enough to lift the magnet or to attract other magnetic objects. In contrast, a piece of genuine, pure hematite will have no noticeable magnetic attraction to a standard magnet.
Visual inspection can also offer clues, as the manufactured material is often unnaturally uniform and perfectly polished, lacking the imperfections found in natural stones. If the item is jewelry, the mere fact that the beads or components snap together with strong force is a clear indicator that the material is the manufactured ferrite. Natural hematite pieces require traditional clasps to stay closed.
A reliable test is the streak test, which involves scratching the sample on a piece of unglazed porcelain. Authentic hematite leaves a distinctive red to reddish-brown powder on the plate. The synthetic magnetic material, while sometimes formulated to produce a red streak, will often leave a gray or black mark, depending on the exact composition of the ceramic.