Formation of natural gypsum megacrystals in Naica, Mexico

  title={Formation of natural gypsum megacrystals in Naica, Mexico},
  author={Juan Manuel Garc{\'i}a‐Ruiz and Roberto Villasuso and Carlos Ayora and {\`A}ngels Canals and Ferm{\'i}n Ot{\'a}lora},
Exploration in the Naica mine (Chihuahua, Mexico) recently unveiled several caves containing giant, faceted, and transparent single crystals of gypsum (CaSO4•2H2O) as long as 11 m. These large crystals form at very low supersaturation. The problem is to explain how proper geochemical conditions can be sustained for a long time without large fluctuations that would trigger substantial nucleation. Fluid inclusion analyses show that the crystals grew from low-salinity solutions at a temperature of… 
Twinning is the key aspect of giant gypsum crystals in Naica
The giant gypsum crystals discovered in 2000 at Naica (Mexico) have been since them a source of deep fascination not only because of their look, but also due to the wealth of scientific information
Preliminary U/Th dating and the evolution of gypsum crystals in Naica caves (Mexico)
The origin and the evolution of giant selenite crystals in Naica caves, together withthe understanding of their growthmechanisms, is one of the aims of the international multidisciplinary research,
Evolution of the Astonishing Naica Giant Crystals in Chihuahua, Mexico
Calcium sulfate (CaSO4) is one of the most common evaporites found in the earth’s crust. It can be found as four main variations: gypsum (CaSO4∙2H2O), bassanite (CaSO4∙0.5H2O), soluble anhydrite, and
What will be the future of the giant gypsum crystals of Naica mine?
  • P. Forti
  • Environmental Science
    Special Publications
  • 2017
Abstract The mine caves of Naica (Chihuahua, Mexico) are famous because they host large gypsum crystals. Mine works intersected new caves hosting the largest crystals in the world in the year 2000.
Ultraslow growth rates of giant gypsum crystals
An advanced high-resolution white-beam phase-shift interferometry microscope is designed to measure growth rates of crystals at very low supersaturation values to gain a better understanding of crystal growth processes occurring at a geological timescale.
Unraveling the Sulfate Sources of (Giant) Gypsum Crystals Using Gypsum Isotope Fractionation Factors
We combine newly determined isotope fractionation factors of gypsum precipitated in the laboratory with the isotopic compositions of natural anhydrite and gypsum to unravel the sulfate sources of the
The origin of large gypsum crystals in the Geode of Pulpí (Almería, Spain)
The Geode of Pulpí (Almería, Spain) is an ∼11 m3 ovoid cavity, the walls of which are covered with meter-sized idiomorphic and highly transparent gypsum (CaSO4●2H2O) crystals. We performed a
Determining gypsum growth temperatures using monophase fluid inclusions—Application to the giant gypsum crystals of Naica, Mexico
Determining the formation temperature of minerals using fluid inclusions is a crucial step in understanding rock-forming scenarios. Unfortunately, fluid inclusions in minerals formed at low
Gypsum Precipitation under Saline Conditions: Thermodynamics, Kinetics, Morphology, and Size Distribution
Gypsum (CaSO4·2H2O) is the most common sulfate mineral on Earth and is also found on Mars. It is an evaporitic mineral that predominantly precipitates from brines. In addition to its precipitation in


Formation of gigantic gypsum crystals
Fluid inclusions and stable isotopes of giant transparent gypsum crystals in a huge geode recently discovered in Pulpí (SE Spain) are useful tools for explaining its geological formation. Fluid
Alunite, Natroalunite and Hydrated Halloysite in Carlsbad Cavern and Lechuguilla Cave, New Mexico
Members of an alunite-natroalunite solid solution series occur in intimate association with hydrated halloysite in deposits within caves of the Guadalupe Mountains, namely Carlsbad Cavern and
Ore genesis in the Naica district, Chihuahua, Mexico
In the Naica mining district of N-central Mexico, pyrometasomatic and mesothermal replacement bodies of base-metal sulfides with minor amounts of Ag and Au occur in a thick sequence of locally
Compositionally distinct, saline hydrothermal solutions, Naica Mine, Chihuahua, Mexico
Naica is a chimney-manto, limestone-replacement, skarn-sulfide deposit typical of those that have yielded much of the silver, lead, and zinc production of the western hemisphere. Fluid inclusions in
Strontium Geochemistry of Modern and Ancient Calcium Sulphate Minerals
The study of Sr+2 distribution in calcium sulphate rocks has been extensive, but largely descriptive. This paper demonstrates the complexity of Sr+2 diagenesis in sedimentary gypsum and anhydrite in
High-temperature, carbonate-hosted Ag-Pb-Zn(Cu) deposits of northern Mexico
The high-temperature, carbonate-hosted Ag-Pb-Zn(Cu) deposits of northern Mexico occur in thick carbonate-dominant Jurassic-Cretaceous basinal sedimentary sequences floored by Paleozoic or older
Sulfur-Isotope Geochemistry of Petroleum, Evaporites, and Ancient Seas
It has now been established that considerable sulfur-isotope fractionation occurs in the biological sulfur cycle and that the bacterial reduction of sulfate, which leads to the enrichment of S34 in
The Nucleation Kinetics of Calcium Sulfate Dihydrate in NaCl Solutions up to 6 m and 90°C
Abstract Induction periods for the nucleation of calcium sulfate dihydrate were experimentally determined as a function of supersaturation in NaCl solutions from 0 to 6 m at 25°C and in 3.0 m NaCl
Measuring induction period for calcium sulfate dihydrate precipitation
Homogeneous nucleation of CaSO{sub 4}{center_dot}2H{sub 2}O (gypsum) based on an optical diagnostic technique was studied within a supersaturation range of 1--4 at 25--90 C. The experiments were
The Gypsum-Anhydrite Equilibrium at One Atmosphere Pressure
The equilibrium temperature for the reaction CaSO*l4*s.2H*l2*sO=CaSO* l4*s+2H*l2*sO*l(liq. soln)*s has been determined as a function of activity of H* l2*sO (a*lH*l2*sO*s) of the solution. Synthetic