TERRIUM — A mineralogy cabinet

Cuarzo

Cuarzo is a mineral with formula SiO₂, in the Silicatos [Tectosilicatos (Grupo Cuarzo)] group. This specimen comes from Madirobe deposit, Antsalova, Besalampy, Melaky, Madagascar and joined the Terrium collection in 2025.

Cuarzo from Madirobe deposit, Antsalova, Besalampy, Melaky, Madagascar — Terrium

Description

Smoky sceptre quartz with exceptional transparency and vitreous lustre. Internal petroleum inclusions emit intense greenish-yellow fluorescence under ultraviolet light.

History of this specimen

I bought this small specimen from a Chinese vendor for €1. In the market this material is known as "Cuarzo luciérnaga" or "Fire Fly Quartz", a trade name coined after this Madirobe find was presented as a world novelty at the 2023 Tucson show.

About Cuarzo

Quartz from this locality is characterised by trapping hydrocarbons in "three-phase" cavities, so called because they simultaneously contain three states of matter: liquid (fluorescent crude oil), gas (a methane bubble) and solid (bitumen or asphalt). They are genuine geological time capsules that captured the fluids present during crystallisation.

About the locality

Madirobe is a recent deposit in the Besalampy district. Unlike the classic petroleum-bearing quartz from Pakistan (Balochistan), those from Madagascar commonly show sceptre or fenster habits and exceptionally vivid fluorescence, which led to their commercial nickname "fireflies".

Technical data

Catalogue No.
0018
Composition
SiO₂
Name
Cuarzo
Group
Silicatos [Tectosilicatos (Grupo Cuarzo)]
Category
Lucimera
Associations
petróleo
Mine
Madirobe deposit
District / Municipality
Antsalova
Province
Besalampy
Region
Melaky
Country
Madagascar
Size (cm)
2.7 x 1.1 x 0.8
Weight
4.3 g
Acquired
2025
Etymology
From German "Quarz", an old term of uncertain origin, possibly Slavic.
Quality
Muy buena
Value trend
Estable

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