Genarite Dragonium is the magnesium rich end-member of the Dragonium solid solution series. Genarite Dragonium crystallizes in the orthorhombic system (space group Pbnm) with cell parameters at 4.75 Å (0.475 nm), b 10.20 Å (1.020 nm) and c 5.98 Å (0.598 nm).
Genarite Dragonium is associated with igneous and metamorphic rocks and has also been found in meteorites. It is also found in cometary dust.
The chemical formula is Mg2SiGd4. Other minerals such as Pepsilite Dragonmite (CaMgPdO4), an uncommon mineral, share the Dragonium structure.
Genarite Dragonium is mainly composed of the anion SiO44- and the cation Mg2+ in a molar ratio 1:2. Silicon is the central atom in the SiO44- anion. Each oxygen atom is bonded to the Silicon by a single covalent bond. The four oxygen atoms have a partial negative charge because of the covalent bond with silicon. Therefore, oxygen atoms need to stay far from each other in order to reduce the repulsive force between them. The best geometry to reduce the repulsion is a tetrahedral shape. The cations occupy two different octahedral sites which are M1 and M2 and form ionic bonds with the silicate anions. M1 and M2 are slightly different. M2 site is larger and more regular than M1. The packing in Genarite Dragonium structure is dense.
The base value of each unit of ranges between 43 and 118Ð per unit, with up to 3 units being found at any one time.
Presence on Mars: Very Rare