Mellite, also known as honey-stone or mellite, is a rare stone belonging to the class of organic compounds or organic stones, according to the Nickel-Strunz classification. It was discovered in the year 1789 in Artern, a city in the state of Thuringia, Germany.
Subsequently, specimens were found in Austria, Russia, the Czech Republic and Hungary. The name of the crystal comes from the Greek meli, which means “honey”, alluding to its color.
On this occasion, we will show you all physical and chemical properties of this unusual mineral, including its occurrence, formation, and major deposits around the world.
Properties and characteristics of the mellite stone
Mellite stone is an aluminum salt of mellitic acid, chemically identified as a aluminum benzene hexacarbonate hydrate. Its chemical formula is Al2C.6(COO)616H2O.
The main colors of this mineral are honey yellow, brownish red and reddish, with some rare white and colorless specimens. Although the melita has a uniaxial optical character, occasionally, biaxial specimens are presented.
The crystalline system of this stone is tetragonal, and consists of dipyramidal, prismatic and elongated crystals. It can also present as nodules and coatings. The mellite hardness is 2 to 2.5 on the Mohs scale, with a conchoidal fracture and a resinous to vitreous luster.
| mellita | Physical and chemical properties |
|---|---|
| class, group | organic stone, organic compound |
| Formula: | Al2[C6(COO)6] 16H2O |
| Color: | Honey to waxy yellow, brown to reddish, gray, rarely white; colorless to pale yellow in transmitted light. |
| Gloss: | Vitreous, Resinous, Oily |
| Hardness: | 2 – 2½ |
| Specific Gravity: | 1.64 |
| glass system: | tetragonal |
| Fracture | Conchoid |
| Stripe | White |
These stones are sectile, which means that they can be easily cut with a knife. The crystals of this stone can produce the pyroelectric effect, that is, they can generate electrical current if exposed to heat.
Mellite crystal fluorescence is white or light blue. when exposed to ultraviolet light shortwave. In the medium of long wave ultraviolet light, fluorescence is lemon yellow.
The mellitas of German origin can present a light blue fluorescence. Meanwhile, the varieties from Russia present a faint brown fluorescence.
Meaning of the mellite stone
According to different cultures, the yellow color in stones or gems is linked to communication and the sun as a protective element. It is claimed that this stone can enhance communication with the inner “self” and with other people, allowing people to have more balance when expressing their emotions and feelings.
These claims are not supported by any scientific study, and they simply belong to the beliefs of various cultures around the world.
Origin, formation and deposits of the mineral mellite
the mineral mellite appears as a very unusual secondary mineral in deposits of lignite and coal. These deposits are rich in aluminum. Aluminum usually comes from clay.
The formation of the mellite stone occurs through an inorganic process, which includes the decomposition and compression of organic material. However, the formation of this stone not produced from living organisms. The process occurs with decomposed plant matter.
Few deposits or locations are known for the mineral mellite. Most of this ore comes from the Csordakúti mine, located in the Bicske-Zsámbéki basin, Hungary. Other major locations include Bohemia and Moravia, in the Czech Republic; the Paris Basin, in France; the towns of Bitterfeld and Artern, in Germany, and Tula, Russia.
Uses of the mellite gem
The most transparent variety of the mellite stone, correctly cut, can serve as a gem. However, its low value makes it practically zero use in jewelry.
There are some ornamental pieces carved with this glass, whose size usually varies from 6 to 10 cm in height. Due to their composition, these parts are not usually damaged by contact.
Some researchers have synthesized the mellite stone for various studies in the area of geochemistry. Although these synthetic gems can be found on various sites on the Internet, these specimens are imitations that are more related to glass.