I-Ming Chou J. Dubessy M.-C. Caumon F. Rull Christian Schmidt 2012 In this chapter, we describe the hydrothermal diamond-anvil cell (HDAC), which is specifically designed for experiments on systems with aqueous fluids to temperatures up to ~1000ºC and pressures up to a few GPa to tens of GPa. This cell permits optical observation of the sample and the in situ determination of properties by ‘photon-in photon-out’ techniques such as Raman spectroscopy. Several methods for pressure measurement are discussed in detail including the Raman spectroscopic pressure sensors a-quartz, berlinite, zircon, cubic boron nitride (c-BN), and ¹³C-diamond, the fluorescence sensors ruby (α-Al₂O₃:Cr³⁺), Sm:YAG (Y₃Al₅O₁₂:Sm³⁺) and SrB₄O₇:Sm²⁺, and measurements of phase-transition temperatures. Furthermore, we give an overview of published Raman spectroscopic studies of geological fluids to high pressures and temperatures, in which diamond anvil cells were applied. application/pdf en Mineralogical Society Chapter 7: The hydrothermal diamond anvil cell (HDAC) for Raman spectroscopic studies of geological fluids at high pressures and temperatures chapter