ライフサイエンスコーパス: aragonite

1 of calcium carbonate (including calcite and aragonite).

2 g, comparable to single crystals of geologic aragonite.

3 the lenses of which are made of birefringent aragonite.

4 rm, and with time crystallizes to calcite or aragonite.

5 than the crystalline polymorphs vaterite or aragonite.

6 are confirmed by electron diffraction to be aragonite.

7 her, close to those measured for calcite and aragonite.

8 of Sr/Ca ratios revealed the particles to be aragonite.

9 lline polymorphs of CaCO(3), calcite, and/or aragonite.

10 activation was followed by precipitation of aragonite.

11 or bulk, where they gradually crystallize to aragonite.

12 chiral, which has not yet been reported for aragonite.

13 al increase in shell calcite and decrease in aragonite.

14 te, constructs its skeleton from calcite and aragonite.

15 al walls are covered by fine-grained fibrous aragonite.

16 comprised of the densest CaCO(3) polymorph, aragonite.

17 do not favor the inorganic precipitation of aragonite.

18 required for supersaturation with respect to aragonite.

19 clusively of the calcium-carbonate polymorph aragonite.

20 comprised of the most dense CaCO3 polymorph, aragonite.

21 create a framework for the precipitation of aragonite.

22 g calcite and an outer structure composed of aragonite.

23 m orientation) and an overall weaker CPO for aragonite (2.4 times random orientation) with a high deg

24 rvations were undersaturated with respect to aragonite, 28% of observations had a pH(T) less than 7.8

25 easing phase stability, are: 20% calcite, 6% aragonite, 60% high-Mg calcite, and 14% amorphous carbon

26 For the case of aragonite, 95% of the spectrophotometric aragonite satur

27 earl oysters and abalone, consists mostly of aragonite (a form of CaCO3), a brittle constituent of re

28 e we report a reversible temperature-induced aragonite-amorphization transition in CaCO(3) at 3.9-7.5

29 bout 4.05 angstroms in strontium-substituted aragonite and at about 4.21 angstroms in strontianite.

30 the thermodynamically favored calcite (both aragonite and calcite are CaCO(3) polymorphs).

31 We show that belemnites precipitated both aragonite and calcite in warm, open ocean surface waters

32 hydrated and dehydrated forms of ACC in the aragonite and calcite layers of Mytilus edulis shells cu

33 to intervals when seawater chemistry favored aragonite and calcite precipitation, respectively.

34 h 3D, X-ray tomography structures of natural aragonite and calcite shells.

35 The first appearances of aragonite and calcite skeletons in 18 animal clades that

36 eveal that the inner wall comprises a mix of aragonite and calcite, explaining these elevated Sr/Ca r

37 ate saturation horizon) and precipitate both aragonite and high-Mg calcite, however, their mode of bi

38 tiary through the present (40 to 0 Ma), when aragonite and MgSO4 salts were the dominant marine preci

39 er temperature, salinity, light attenuation, aragonite and oxygen down to 1500 m deep.

40 Nacre, a composite made from biogenic aragonite and proteins, exhibits excellent strength and

41 mineralization resulted in the formation of aragonite and/or calcite.

42 n of calcite (prismatic layer, as opposed to aragonite) and organic matrix, providing potentially hig

43 ly three polymorphs of pure CaCO(3)-calcite, aragonite, and vaterite-were known to exist at ambient c

44 high-magnesium calcites (HMC) dominates over aragonite (Arag) and low-magnesium calcite (LMC) and con

45 Both delta(13)C and delta(18)O of the aragonite are enriched above the expected kinetic fracti

46 AP7 is an extracellular aragonite-associated protein of the nacre layer of the m

47 Interestingly, 95% of the aragonite-associated protein sequences were found to con

48 Of 39 mollusk aragonite-associated protein sequences, 100% contain at

49 Collectively, our findings indicate that aragonite-associated proteins have evolved signature seq

50 pecies while also hinting at the presence of aragonite at the dorsal protrusion region of the Eudicel

51 y system that includes hundreds of eyes with aragonite-based lenses.

52 in-protein assembly processes and ultimately aragonite biosynthesis.

53 their guts ("low" and "high" Mg-calcite and aragonite), but that very fine-grained (mostly < 2 mum)

54 ecific gravity related to the replacement of aragonite by calcite.

55 inal step consists of partial replacement of aragonite by dolomite, possibly in neutral to slightly a

56 raphy and map the c-axis orientations of the aragonite (CaCO(3)) crystals.

57 Reef-building corals and their aragonite (CaCO(3)) skeletons support entire reef ecosys

58 tructure, comprising alternating transparent aragonite (CaCO(3)) tablets and thinner organic polymer

59 d stony or scleractinian corals, are made of aragonite (CaCO(3)).

60 hells, is a biomineral lamellar composite of aragonite (CaCO3) and organic sheets.

61 using ocean acidification, lowering seawater aragonite (CaCO3) saturation state (Omega arag), with po

62 ous for hours, and finally, crystallize into aragonite (CaCO3).

63 on these relations, we estimate that abiotic aragonite calcification may account for 15 +/- 3% of the

64 es, are comprised of the CaCO(3) polymorphs (aragonite, calcite and vaterite), which can occur either

65 Geochemical analysis indicated aragonite, calcite, and dolomite precipitation under res

66 most common polymorphs of calcium carbonate-aragonite, calcite, and vaterite-which can affect the ec

67 NanoSIMS mapping across the aragonite-calcite interface indicates an organic layer b

68 e show that ocean geochemistry, particularly aragonite-calcite seas, drives patterns of morphological

69 The ratio of aragonite/calcite at WOL and delta(18)O at SL suggest th

70 (4) abundance was negatively correlated with aragonite/calcite, suggesting that severe moisture defic

71 ome mollusk shells, has alternating biogenic aragonite (calcium carbonate, CaCO(3)) tablet layers and

72 ron isotopic and elemental analysis of coral aragonite can give important insights into the calcifica

73 interference color generated from repetitive aragonite-conchiolin double layers on colorless nacreous

74 were also found to possess primarily normal, aragonite-containing otoliths, while hatchery-reared juv

75 fication, the proposed galvanizing effect of aragonite could be weakened in the future, and calcite d

76 f these proteins are incorporated into their aragonite crystal structure.

77 We report aragonite crystallization in primary cell cultures of a

78 earl biomineralization, evidenced by thinner aragonite crystals and the presence of abnormal biominer

79 on "toolkit," an organic scaffold upon which aragonite crystals can be deposited in specific orientat

80 In addition, patches of original aragonite crystals define the former position of the end

81 nsmission electron microscopy (TEM) study of aragonite crystals from various localities, we show that

82 e, skeletal proteins are embedded within the aragonite crystals in a highly ordered arrangement consi

83 It is generally accepted that aragonite crystals of biogenic origin are characterized

84 ing lateral growth of colonies and growth of aragonite crystals under the calcifying tissue.

85 cess leads to the formation of extracellular aragonite crystals.

86 sformation of amorphous calcium carbonate to aragonite, demonstrating the co-existence of both amorph

87 by stabilizing magnesium calcite to inhibit aragonite deposition, PfN44 participated in P. fucata sh

88 and stabilized magnesium calcite to inhibit aragonite deposition.

89 Here, we investigate the role of aragonite dissolution on the early diagenesis of calcite

90 We show that otoliths (aragonite ear bones) of young fish grown under high CO2

91 the sediment, and previously overlooked, (4) aragonite encrustations formed rapidly around decaying o

92 mposition to depth changes in the calculated aragonite equilibrium oxygen isotope values implies shal

93 ite could completely transform to calcite or aragonite, except those from DETA.

94 Parameter sweeps show that the aragonite fibers' size (~1 um diameter), morphology (lon

95 We show that, locally, aragonite fluxes to the seafloor could be sufficient to

96 aters to remain over the saturation level of aragonite for long periods of time.

97 il CO(2) release may be also due to enhanced aragonite formation (by 300% for Ca-poor and 90-200% for

98 d this correlates with known aggregation and aragonite formation functions in three experimentally te

99 dic matrix protein named PfN44 that affected aragonite formation in the shell of the pearl oyster Pin

100 he early reaction stages taking place during aragonite formation were identified in a highly supersat

101 ins and polysaccharides were shown to induce aragonite formation, rather than the thermodynamically f

102 ive to control scenarios and does not induce aragonite formation.

103 We demonstrate that aragonite forms closest to isotopic equilibrium such tha

104 ystyrene spheres along with calcite, whereas aragonite forms in solution via homogeneous nucleation.

105 Within each window, aragonite forms narrow fibrous prisms perpendicular to t

106 matic regions are consistently identified as aragonite ([Formula: see text] cm(-1)) and calcite ([For

107 t prehistoric processing methods in skeletal aragonite from archaeological shell midden assemblages.

108 ystallographic and geochemical signatures of aragonite giant clam shells Tridacna squamosa from high

109 with a high degree of twinning (45%) of the aragonite grains.

110 es are consistent with a transition to (001) aragonite growth on a (1014) calcite surface.

111 tely biogenic anhydrous ACC --> vaterite --> aragonite --> calcite.

112 ipitate calcium carbonate extracellularly as aragonite in a calcifying medium between the calicoblast

113 demonstrate that in vitro crystallization of aragonite in coral cell cultures is possible, and provid

114 report stable oxygen isotope measurements of aragonite in fish otoliths--ear stones--collected across

115 leation barrier surpasses that of metastable aragonite in solutions with Mg:Ca ratios consistent with

116 ing coralline that prevents the formation of aragonite in the living skeletal cell walls.

117 ify for the first time the flux of inorganic aragonite in the water column.

118 (2+) stoichiometrically but also precipitate aragonite in vitro in seawater at pH 8.2 and 7.6, via an

119 ular assemblies that nucleate single-crystal aragonite in vitro.

120 Inorganic precipitation of aragonite is a common process within tropical carbonate

121 to which the Gibbs free energy of twin-free aragonite is close to that of periodically twinned arago

122 Abiotic CaCO(3) precipitation in the form of aragonite is potentially an important feedback mechanism

123 This stabilization of aragonite is remarkable in that it occurred in the prese

124 Aragonite is the dominant CaCO3 mineral present in the l

125 text]300 nm) of nacre's building blocks, the aragonite lamellae (or platelets), and (ii) the imbricat

126 ples that Sr randomly replaces Ca within the aragonite lattice.

127 We also demonstrated how to predict the aragonite layer thickness and estimate the conchiolin re

128 luded such patterns are mainly determined by aragonite layer thickness.

129 chiton Acanthopleura granulata has the first aragonite lenses ever discovered.

130 CO(3)), CO(3)(2-) (<= 80 umol/kg), and Omega aragonite (<= 1) closer to the ranges reported as optima

131 atalyst and natural source of CaCO(3) in its aragonite microcrystalline form with fixed CO(2), was op

132 investigated the crack behavior in geologic aragonite mineral (pure monocrystal) and found that the

133 The formation of aragonite mineral in the mollusk shell or pearl nacre re

134 s fracture with a delamination effect on the aragonite mineralogical structure of the shell.

135 their exposure to waters undersaturated for aragonite more likely in the near future given that thes

136 thicker, more calcified shells with a higher aragonite (nacreous layer) proportion were deposited, wh

137 ous and crystalline material within the same aragonite needle.

138 he saturation state of the carbonate mineral aragonite of surface waters.

139 y ranged from 2299 to 2346 mumol kg(-1), and aragonite Omega ranged from 1.35 to 2.44.

140 on via reductions in the saturation state of aragonite (Omega(Ar)) in seawater.

141 agonite undersaturation [saturation state of aragonite (Omega(arag)) < 1].

142 known to cause the nucleation and growth of aragonite on calcite seed crystals in supersaturated sol

143 r flow tops mineralizes to ankerite-siderite-aragonite on month-year time scales, with 60% of the 977

144 an organic template for biomineralization of aragonite on the calcite layer.

145 ral walls separating autozooid chambers have aragonite only on their distal side.

146 ase, which is progressively transformed into aragonite or calcite in biomineralization of marine inve

147 mation in sea urchin spicules, and not proto-aragonite or poorly crystalline aragonite (pAra), as exp

148 oxygen and strontium isotope ratios of four aragonite otoliths collected from the Fox Hills Formatio

149 ts displaying three generations of ikaite-to-aragonite palisade crystals, now recrystallized to calci

150 nd not proto-aragonite or poorly crystalline aragonite (pAra), as expected for aragonitic nacre.

151 Second, aragonite patches nucleate in close proximity to sulfate

152 blet sliding primarily resisted by nanoscale aragonite pillars from the following sliding resisted by

153 propagating crack, surprisingly, invades the aragonite platelet following a zigzag crack propagation

154 re, which tunes crack propagation inside the aragonite platelet in an intergranular manner.

155 ghening origin of previously-thought brittle aragonite platelet is ascribed to its unique nanoparticl

156 trast with the intergranular cracking in the aragonite platelet of nacre.

157 It has been widely thought that the ceramic aragonite platelets in nacre invariably remain shielded

158 ction along the biopolymer interface between aragonite platelets.

159 ium carbonate precipitates as the metastable aragonite polymorph in marine environments, rather than

160 he reef and deposit calcium carbonate as the aragonite polymorph, stabilized into a continuous calcar

161 sensitivity equivalent to that of laboratory aragonite precipitated at equilibrium and the nighttime

162 iment is higher than expected for calcite or aragonite precipitating from seawater.

163 onsists of primary (1) inorganic calcite and aragonite precipitating in the surface-water, (2) biogen

164 (13)C(oto) records both the fractionation by aragonite precipitation and the variation in hypoxia tra

165 te in the tropics by 30 percent and biogenic aragonite precipitation by 14 to 30 percent.

166 ve calcium carbonate sand despite widespread aragonite precipitation from platform surface waters.

167 We show that aspartic acid inhibits aragonite precipitation from seawater in vitro, at the p

168 thus, this phenomenon cannot be explained by aragonite precipitation kinetics.

169 solates, delayed ALP activation, and delayed aragonite precipitation.

170 proach to resolve the long-standing "calcite-aragonite problem"--the observation that calcium carbona

171 As aragonite producers are particularly vulnerable to ocean

172 des with a shelf-wide cessation of inorganic aragonite production and a switch to carbonate sedimenta

173 Early-stage reaction mechanisms for aragonite-promoting systems are relatively unknown compa

174 synthetic calcite rhombohedra, but never in aragonite pseudohexagonal prisms, synthetic or biogenic,

175 vitro is highly challenging, because Mg-free aragonite, rather than calcite, is the favored product i

176 requisite for the formation of shallow water aragonite-rich sediments on the NWS.

177 rm deposits are produced through admixing of aragonite-rich sediments, which have relatively positive

178 pacts and projected ocean thermal stress and aragonite saturation (a proxy for ocean acidification).

179 been growing for their entire life under low aragonite saturation (Omega(sw): 0.77-1.85).

180 ificantly along a natural gradient in pH and aragonite saturation (Omegaarag).

181 Further, kelp fragments increased pH and aragonite saturation and decreased pCO(2) during the day

182 were likely adapted to high temperature/low aragonite saturation conditions suggests that reefs that

183 Northeast Pacific, combined with the shallow aragonite saturation horizon (ASH) and high carbonate di

184 am per year, are observed beginning near the aragonite saturation horizon.

185 hree stressors: high human impact, declining aragonite saturation levels and elevated thermal stress.

186 dification could result in reductions of the aragonite saturation levels during future decades, actin

187 displayed frequent decoupling between pH and aragonite saturation state ( (arg)) suggesting pH-based

188 temperatures (28 C) by elevating pH(cf) and aragonite saturation state ( (cf)) in support of calcifi

189 prolonged stratification resulting in a high aragonite saturation state (Omega(Ar) >= 4).

190 IC), partial pressure of CO(2) (pCO(2)), and aragonite saturation state (Omega(Ar)) and are compared

191 reef flat corals reach net dissolution at an aragonite saturation state (Omega(AR)) of 2.3 (95% confi

192 )), hydrogen ion concentration ([H(+)]), pH, aragonite saturation state (Omega(ara)), and RF within p

193 e project absolute and percentage changes in aragonite saturation state (Omegaarag) for the period be

194 We also show that corals can achieve a high aragonite saturation state (Omegaarag) in the calcifying

195 or Seamount Chain at depths of 535-732 m and aragonite saturation state (Omegaarag) values of 0.71-1.

196 utotrophy (%DO > 100) and dramatic shifts in aragonite saturation state critical to shell-forming org

197 ntration of carbon dioxide will decrease the aragonite saturation state in the tropics by 30 percent

198 ion has already been observed in areas where aragonite saturation state is ~1.

199 However, while Porites corals increase the aragonite saturation state of the calcifying fluid (Omeg

200 , bottom temperature, bottom oxygen, pH, and aragonite saturation state through model hindcasts, refo

201 nal reductions in subsurface oxygen, pH, and aragonite saturation state, by up to 50 mmol m(-3), 0.09

202 cation rates of corals because of decreasing aragonite saturation states (Omega(arag)).

203 of aragonite, 95% of the spectrophotometric aragonite saturation states (Omega(Aspec)) were within +

204 lcification fluid [CO3(2-)] and induces high aragonite saturation states, favourable to the precipita

205 etric [CO3(2-)] methodology and to determine aragonite saturation states.

206 to the high-density inter-polyp walls where aragonite saturation was ~ 5 times that of external seaw

207 esents [CO3(2-)] slightly above the level of aragonite saturation, and the expected anthropogenic aci

208 h in situ [CO3(2-)] compared to the expected aragonite saturation.

209 87)Sr/(86)Sr, and the change from calcite to aragonite seas, KCl to MgSO(4) evaporites, and greenhous

210 If large quantities of aragonite settle and dissolve at the seafloor, this repr

211 ense research interest due to their external aragonite shell and vulnerability to ocean acidification

212 r ocean acidification, because their fragile aragonite shells are susceptible to increasing ocean aci

213 ontium ((87)Sr/(86)Sr) isotope ratios in the aragonite shells of four native freshwater mussel specie

214 We measured the Delta47 of aragonite shells of the freshwater gastropod Viviparus l

215 Paragenetic insights for the timing of aragonite, silica, and fibrous zeolites are clarified ba

216 Corallimorpharians escaped extinction from aragonite skeletal dissolution, but some modern stony co

217 of oceanic CO(2), which would have impacted aragonite solubility.

218 model requires the presence of an additional aragonite source.

219 We show in both coral and synthetic aragonite spherulites that crystal growth by attachment

220 nce of AP7 alone and did not require typical aragonite stabilization agents such as Mg(II), other nac

221 )) and then tested it on "clean" calcite and aragonite stalagmite samples from cave KNI-51 in the Aus

222 ome strontium substitutes for calcium in the aragonite structure, at concentrations of about 7500 par

223 ite is close to that of periodically twinned aragonite structure.

224 unreported morphological features including aragonite subdomains encapsulated in extensions of the p

225 on, this OM did not inhibit the formation of aragonite suggesting there is an as yet unidentified pro

226 In combination with a low aragonite supersaturation in the ocean, this could have

227 roscopy experiments revealing that stacks of aragonite tablet crystals in nacre are misoriented with

228 mposite biomineral that contains crystalline aragonite tablets confined by organic layers.

229 are attributable to the periodic stacking of aragonite tablets known as nacre.

230 ogression to undersaturation with respect to aragonite that could compromise the conservation of the

231 oluble, is widespread at the seafloor, while aragonite, the more soluble, is rarely preserved in mari

232 mineral content of about 99% (by volume) of aragonite, the shell of Strombus gigas can thus be consi

233 is primarily composed of a brittle mineral, aragonite, the structure is highly damage tolerant and c

234 rious localities, we show that in geological aragonites, the twin densities are comparable to those o

235 We monitored the conversion of aragonite to calcite in water by comparing single and mi

236 os consistent with modern seawater, allowing aragonite to dominate the kinetics of nucleation.

237 We demonstrate that the enhanced aragonite-to-calcite conversion in mixed polymorph suspe

238 eserves in sustaining CWC growth in spite of aragonite undersaturated conditions (deep corals) in the

239 st open-ocean basin to experience widespread aragonite undersaturation [saturation state of aragonite

240 Consequently, end-of-century aragonite undersaturation is ubiquitous under the three

241 water that is undersaturated with respect to aragonite upwelling onto large portions of the continent

242 s of CaCO(3) are known-3 anhydrous: calcite, aragonite, vaterite, and 3 hydrated: ikaite (CaCO(3).6H(

243 Of the four polymorphs, calcite, aragonite, vaterite, and amorphous CaCO(3), vaterite is

244 und that in addition to Mg-calcite up to 30% aragonite were present in the skeleton.

245 greater solubility, research has shown that aragonite, whose contribution to global pelagic calcific

246 trikingly similar to natural nacre: lamellar aragonite with interspersed N16N layers.

247 onate minerals consist mainly of calcite and aragonite, with minor ankerite and dolomite.

248 This supports non-classical formation of aragonite within both a synthetic and biological context