1.55" Highly Fluorescent Hyalite Opal on Aquamarine Crystals - Namibia

Aquamarine is a blue-green variety of beryl. Oddly enough, it owes its color to iron(II) and iron(III) cations within the crystal lattice, of which iron(II) is responsible for the blue color, while iron(III) is responsible for the yellow color. The color vibrance and hue are dependent on the concentration of these cations, or lack of one or the other. The presence of both cations in the right position within the crystal lattice, can result in a deep blue colored crystal that is known as "maxixe".

Hyalite is a transparent to translucent variety of opal that typically bears a globular structure. An amorphous form of silica (SiO2), hyalite opal forms as a volcanic sublimate in volcanic or pegmatic rock and is thereby considered a mineraloid. It can be referred to as water opal, jalite, or even Muller's glass, named after the man who discovered it, Franz-Joseph Müller von Reichenstein. It has a hardness of 5.5–6 on the Mohs scale and exhibits conchoidal fracturing.