Table A : Properties of Aquaprase™

Colour range’Aqua’ blue - greenish blue - bluish green - to green (low to medium saturation) - with and without banding / matrix
TransparencySemi-transparent to translucent
Refractive index1.53 - 1.54 (range)
Specific gravity2.50 - 2.58 (range)
UV fluorescenceBluish green to yellowish green (long wave and short wave) – mostly patchy; DiamondView imaging reveal interesting fluorescence patterns following the growth structures
Chelsea filterPatchy brownish-red (green inclusions appeared stronger red); bluer samples - red to pink
Absorption spectrum (desk model)Absorption band in yellow region; sharp lines in red
Raman spectraConsistent with chalcedony: Peaks at ~ 205, 260, 355, 400, 463, 501 (moganite), 692, 798, 1162 cm-1. No additional feature was recorded for colour-causing green patches or inclusions.
Absorption spectra (UV-Vis-NIR)Broad absorption bands centred ~ 420 and 600 nm; a shoulder at ~ 643 nm; doublet at ~676 and 679 nm. This absorption pattern (figure 8) is similar to that previously reported for chrome chalcedony and hence, suggested the presence of chromium (e.g. Hyrsl, 1999).
FTIR spectraConsistent with chalcedony: Absorption bands at ~5330-4920 and ~4570-4260 cm-1; complete absorption below ~4150 cm-1
Qualitative EDXRF analysisMajor: Si; Traces: Ca, Cr, Fe, Ni
Source: Gagan Choudhary, GTL Jaipur, India

Table B : Gems Comparisons

Aquaprase, from geochemical data, is a chalcedony with Chromium (300-150 ppm), Nickel (100-60 ppm) and Zinc (70-50 ppm). It is silicate minerals, with chemistry SiO2

Chrysoprase is also a silicate mineral SiO2, an apple-green variety of chalcedony. The colour is caused by tiny inclusions of Ni-bearing layers silicates (willemseite, nepouitr or others).Chrysocolla is a mineral of secondary origin, commonly associated with other secondary copper minerals. It is typically found as glassy botryoidal or rounded masses or bubbly crusts, and as jackstraw mats of tiny acicular crystals or tufts of fibrous crystals. Copper-bearing allophane can look similar. Its chemical formula is (Cu2-xAlx)H2-xSi2O5(OH) 4nH2O.
Source: MichalisFitros (Geologist, University of Patras)
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