缅甸紫色翡翠的致色机理——光谱和色度学研究

采用电子探针分析、能量色散X射线荧光光谱、傅里叶变换红外光谱、紫外-可见光谱和色度学方法等多种手段,对55个缅甸紫色翡翠样品进行了全面分析。结果表明,缅甸紫色翡翠的主要化学成分为SiO₂、Al₂O₃和Na₂O,含量与标准硬玉接近。色度学测试分析显示,缅甸紫色翡翠的彩度C^*主要受色度值a^*控制,而色调角h°主要由色度值b^*控制。缅甸紫色翡翠可分为两种类型:Ⅰ型紫色翡翠主要由Mn³⁺致色,并在紫外-可见-近红外光谱570 nm显示主要吸收带;Ⅱ型紫色翡翠由于Fe²⁺-Ti⁴⁺之间的电荷转移致色,在光谱540 nm和610 nm显示吸收。两种翡翠中均存在Fe³⁺的吸收峰,样品中的全铁含量决定其色调角及明度。     

缅甸抹谷紫方钠石光致变色效应脱色效率研究

光致变色效应是紫方钠石最显著且极具价值的光学特征。本文通过EDXRF、FTIR、UV-VIS-NIR、D65标准光源、照度计以及色度学方法,对缅甸抹谷紫方钠石光致变色效应脱色效率进行了定量研究。紫方钠石的主量元素为Na、Al、Si和O,此外含有少量Cl和S,微量元素可含Ca、K和Fe,UV-VIS-NIR光谱存在472、540和667 nm的3个吸收峰,其中以540 nm吸收强度最大,脱色过程中,其光谱吸收峰峰位不变,但强度随时间逐渐减小,540 nm吸收峰面积在0~80 s与时间呈线性负相关(R²=0.99);脱色过程中,当照度从5000 lx升高至30000 lx时,紫方钠石脱色效率明显升高,明度L^*升高,彩度C^*降低,色品a^*降低且色品b^*升高,色调由紫色向粉色调轻微变化,是电荷转移导致F中心被破坏的直接结果。     

K-H3OFe3(SO4)2(OH)6铁矾的XRD研究

根据X射线衍射(XRD)分析发现: A Fe₃(SO₄)₂(OH)₆(A=K⁺、H₃O⁺)系列铁钒的XRD数据十分相近,难以用XRD区别,需通过能谱(EDS)辅助分析,才能区分此类铁矾。另外,此类铁矾的003和107面网间距d随K⁺含量增大而增大,且呈一元三次方程的关系;而033和220面网间距d随K⁺含量增大而减小,呈一元二次方程的关系。对该现象从铁矾晶体结构方面进行解释:K⁺、H₃O⁺离子位于较大空隙中,且沿着Z轴方向排列,当K⁺、H₃O⁺离子之间相互替换时,会导致该铁矾晶体结构在Z轴方向有较明显的变化。     

浙江临海猫狸岭岩体的成因：年代学、地球化学与Sr-Nd-Hf同位素制约

猫狸岭岩体位于浙江省临海县仙人桥-猫狸岭一带,其主体岩性为石英二长闪长岩、石英二长岩和细粒花岗岩。LA-ICP-MS 锆石U-Pb定年表明石英二长闪长岩和细粒花岗岩的年龄分别为105.6±1.0Ma和104.8±0.9Ma。主量元素组成上,石英二长闪长岩具准铝质、钙碱性和富钾的特征,MgO、Fe₂O₃^T、CaO等含量较高,Mg^#值变化于47.6~50.6;细粒花岗岩同样具富钾和准铝质特征,但偏酸性,MgO、Fe₂O₃^T、CaO等含量相对偏低,Mg^#值变化于41.6~47.0。微量和稀土元素组成上,石英二长闪长岩富集Rb、Th、U、Pb,贫Nb、Ta、P、Ti,且Zr、Hf、Sr含量相对较高,铕负异常不显著（Eu/Eu^*=0.77~0.95）。细粒花岗岩具有相似的微量元素特征,但P、Ti亏损程度更明显,且明显贫Sr,并具一定程度的铕负异常（Eu/Eu^*=0.55~0.78）。石英二长闪长岩和细粒花岗岩具有相似的Sr-Nd同位素组成,I_Sr分别为0.7088和0.7079~0.7088,ε_Nd（t）值分别为-7.57~-7.56和-8.06~-7.95。同时,二者具有大致相似的锆石Hf同位素组成,ε_Hf（t）值分别为-12.2~-6.6和-9.6~-4.4。综合分析表明,猫狸岭石英二长闪长岩和细粒花岗岩最可能是在区域伸展拉张的构造背景下,由底侵或内侵的幔源岩浆与其诱发的壳源岩浆经混合后,并经过不同程度的分异演化,最后在浅成环境侵位的产物。     

扬子地台北缘檬子地区侵入岩年代格架和岩石成因研究

对扬子地台北缘檬子地区发育的辉长苏长岩、角闪辉长岩、花岗闪长岩、石英闪长岩和钾长花岗岩体进行了LA-ICPMS锆石U-Pb定年和Lu-Hf同位素、全岩主量和微量元素分析。结果表明,该区基性和中酸性岩体均形成于新元古代中晚期。其中基性侵入体辉长苏长岩形成于764±38Ma,角闪辉长岩形成于757±32Ma,均属钙碱性系列,轻稀土富集,微量元素原始地幔蛛网图中显示富集大离子亲石元素(LILE,如Ba、La、Ce、Sr等)、具有明显的Nb、Ta负异常和弱的P、Ti具负异常,形成于地幔原始石榴石二辉橄榄岩源区,部分熔融的程度大于10%。锆石Lu-Hf同位素研究揭示辉长苏长岩ε_Hf(t)值变化于+6.92~+13.99,t_DM变化于736~1058Ma,当ε_Hf(t)为最大正值时,对应的t_DM与岩石的形成年龄基本一致;角闪辉长岩ε_Hf(t)变化于+4.74~+14.97,t_DM主体范围变化于707~1214Ma,当ε_Hf(t)具有最大的正值时,t_DM接近于岩石形成年龄。反映出辉长苏长岩和角闪辉长岩在形成过程中,经历了地壳混染作用,最有可能是中元古代地壳的混染。对石英闪长岩年代学测试表明其形成于774±34Ma。花岗闪长岩、石英闪长岩属钙碱性系列,具有相似的稀土和微量元素分布特点,表现为大离子亲石元素富集,亏损高场强元素(Ta、Nb、Y、Yb等)的特点。钾长花岗岩样品属高钾钙碱系列,岩石稀土元素丰度较低,∑REE=105.9×10^-6~133.1×10^-6,轻稀土富集,具有强烈的Eu负异常(δEu=0.03~0.09),微量元素原始地幔标准化表现为大离子亲石元素富集,Ba、Nb、Sr、P、Ti具有明显负异常。石英闪长岩ε_Hf(t)变化于-4.46~+13.10之间,大部分为正值,平均值为+4.80,t_2DM变化于820~1726Ma,平均值为1256Ma,显示其主要为新元古代新生地壳部分熔融的产物,在形成过程中有中元古代地壳物质的参与;钾长花岗岩ε_Hf(t)主体为负值,变化于-16.49~+8.33,平均值为-5.26,t_2DM为943~2080Ma,平均值为1458Ma,显示其主体为古老地壳物质部分熔融的产物,新元古代新生地壳参与较少。结合区域地质特征分析,檬子地区基性和中酸性侵入体形成于活动大陆边缘弧环境,是新元古代勉略洋盆向南俯冲的地质记录。     

藏南洛扎地区淡色花岗岩锆石U-Pb年龄、Hf同位素、地球化学与岩石成因

洛扎岩体位于高喜马拉雅淡色花岗岩带的东部,锆石U-Pb测年显示其形成年龄为17.7Ma。洛扎岩体的岩性主要为电气石二云母花岗岩和电气石白云母花岗岩,岩石富硅(SiO₂为73%~75%)、富钾(K₂O为3.9%~4.9%),强过铝(Al₂O₃为14.5%~15.5%,A/CNK大于1.1),属于高钾钙碱性系列的强过铝淡色花岗岩。岩石具有明显的轻重稀土分异和Eu负异常(Eu/Eu^*=0.57),强烈富集大离子亲石元素,相对亏损高场强元素。岩石具有高Rb/Sr(>4)、低CaO/Na₂O (0.19~0.26)的特征,指示了其源岩为泥质岩石。(⁸⁷Sr/⁸⁶Sr)_t和ε_Nd(t)值的变化范围分别为0.725802~0.727276和-13.4~-12.9; 锆石的ε_Hf(t)变化范围为-13.9~-7.5,其较大的变化范围暗示了洛扎淡色花岗岩源区具有不均一性。洛扎岩体可能的构造-岩石成因是,藏南拆离系的启动使深部减压,致使变泥质岩中的白云母发生脱水熔融而形成淡色花岗岩岩浆。岩浆通过STDS所形成的构造薄弱带上侵,沿STDS主拆离断层分布。所以洛扎淡色花岗岩形成于STDS启动所引起的地壳伸展、快速隆起背景下,构造减压所导致的变质岩中白云母的脱水熔融。     

西藏拉萨地块南缘晚白垩世镁铁质岩浆作用的年代学、地球化学及意义

镁铁质岩石所反映出的壳幔作用信息可以为地壳增生发生的时间和方式提供可靠的证据。本文报道了南部拉萨地块东段朗县至米林之间晚白垩世镁铁质岩石的岩石学、锆石U-Pb年代学、全岩地球化学以及锆石Hf同位素数据。锆石U-Pb定年结果表明,角闪辉长岩侵位于98~88Ma,高Al₂O₃(17.25%~19.46%),低MgO含量(3.89%~5.07%)及Mg^#(44~50),与高铝玄武岩特征相似,属于中钾钙碱性岩石,富集大离子亲石元素(LILE)、亏损高场强元素(HFSE),铕异常不明显(δEu=0.82~1.06),(⁸⁷Sr/⁸⁶Sr)_i值为0.70427,ε_Nd(t)值为3.0,具有高且正的锆石ε_Hf(t)值(+11.8~+17.2)。这些晚白垩世镁铁质岩石可能是来自俯冲板片的沉积物熔体交代地幔楔物质发生部分熔融并经历一定程度镁铁质矿物分离结晶作用产物。     

塔西南其木干早二叠世玄武岩的喷发时代及地球化学特征

塔西南其木干剖面棋盘组玄武岩是塔里木盆地早二叠世大火成岩省西南部的重要组成部分,根据其下伏和上覆砂岩地层的碎屑锆石U-Pb年龄分析可以限定其喷发于~284Ma,相应于柯坪地区开派兹雷克组玄武岩的形成时代。其木干玄武岩的主量元素和Cr、Ni等相容元素含量变化较大,表明其曾经历广泛的橄榄石、辉石和长石结晶分异作用;所研究样品相对富集Th、U和LREE,具有弱-中等程度的Eu负异常 (Eu/Eu^*=0.82~0.99),在微量元素蛛网图上显示Nb-Ta负异常;较低的ε_Nd(t) (-4.8~-3.9) 和ε_Hf(t) (-2.4~-1.6) 值、较高的 (⁸⁷Sr/⁸⁶Sr)_i (0.7078~0.7086)和存在Hf-Nd同位素解耦等特征表明,其木干玄武岩的源区为受远洋沉积物组分交代富集的岩石圈地幔,该富集过程主要与Rodinia超大陆聚合过程有关。总体上,其木干玄武岩的地球化学特征类似于柯坪地区的开派兹雷克组玄武岩,但具有更为富集的Sr-Nd-Hf同位素,暗示了塔里木板块周缘比板内地区可能经受了更强烈的远洋沉积物组分的交代富集。     

广东凡口铅锌矿床赋矿地层稳定同位素研究

广东凡口铅锌矿床是中国著名的大型铅锌矿床。在凡口矿区新发现有类似奥陶系岩性的地层,与寒武系一起构成矿区的浅变质基底,其δ¹³C_V-PDB值为-6.5‰、δ¹⁸O_V-SMOW值为14.9‰,在矿区各地层中最小,受热液作用影响最弱,主要受岩性影响。由深至浅,泥盆系地层的δ¹³C_V-PDB、δ¹⁸O_V-SMOW值逐渐增高、⁸⁷Sr/⁸⁶Sr值逐渐减小,该段岩层的主赋矿层位（D₂d和D₃t）δ¹³C_V-PDB接近零,δ¹⁸O_V-SMOW在18‰左右,稳定同位素的变化除受岩性影响外,主要受后期热液蚀变作用的影响,为成矿提供了一定的前提条件。石炭系（C₂ht）白云岩的δ¹³C平均值为2.17‰,δ¹⁸O平均值为21.9‰,与其他层位性质明显不同,为矿区的盖层。     

河西走廊晚泥盆世地层中冥古宙碎屑锆石的发现

河西走廊地区晚泥盆统中宁组地层中,利用LA-ICP-MS法测年获得了3.9Ga和4.0Ga两颗碎屑锆石,其Th/U依次为1.01和0.58,均为岩浆锆石。两颗锆石稀土元素呈轻稀土(LREE)亏损、重稀土(HREE)富集,均具有Ce正异常,其中4.0Ga锆石具有Eu负异常,3.9Ga锆石无Eu负异常。利用锆石中⁴⁹Ti的含量计算原岩岩浆温度分别为792±36℃(3.9Ga)和967±45℃(4.0Ga)。3.9Ga锆石获得原位Hf同位素结果,¹⁷⁶Hf/¹⁷⁷Hf_i=0.280169,ε_Hf(t)=-3.6,t_DM=4139Ma, t_DM^C=4319Ma。这两颗>3.9Ga碎屑锆石为西北地区首次发现,其微量元素特征说明在冥古宙时地球上可能存在地壳;结合前人古生物和古地磁研究结果,说明河西走廊在晚泥盆世时同澳大利亚西北部可能具有亲缘性。     

Metamerism Appreciation of Jadeite-Jade Green under the Standard Light Sources D65, A and CWF

We tested 288 pieces of the polished cabochon jadeite-jade with high quality green and smooth surfaces using the colorimeter Color i5 based on the CIE 1976 L~*a~*b~* uniform color space. The color changes after alternating three CIE standard light sources D_(65),A and CWF were compared,and the degree of metamerism was evaluated. The results show that the CIE standard light sources D_(65),A and CWF increase the chroma of green and turn bluish green into vivid green,which are similar or to nearly colorless and transparent glass-like samples with fine textures. When the three light sources were individually alternated,the lightness of the jadeite-jades showed little change,but the tone changed significantly. Metamerism occurred only in 3 pairs among the 16 samples that were selected by cluster analysis for quality,and the metamerism colors were highly consistent of L~*D_(65)∈(43.47,46.75),C~*D_(65)∈(65.20,68.80) and ho~*D_(65)∈(138.10,140.23). We can conclude that the jadeite-jade green gradually turns to blue when the color temperature of the light source increases. But when considering both the light sources and the samples,D_(65) is more suitable to be the light source of jadeite-jade green when compared with the light sources CWF and A. Compared with the CIE standard green and high chroma green,high-quality jadeite-jade green has a slight yellow tone,low lightness and high chroma. The special metamerism index decreased to 1 when the light source alternated among D_(65),A and CWF. Therefore,the color of jadeite-jade green might be slightly influenced by alternating of the light sources.     

Differences in the quality of polishing between sound and weathered granites

Aesthetic characteristics are important when rocks are used as construction materials. Among all the surface finishes available, the polished finish is the one which best enhances the rock attractiveness. Colour (C), roughness (R) and gloss (G) are surface properties usually used to assess the rock polishing. In this research, the CRG properties were assessed in polished samples of three ornamental granites with different textures and physical–mechanical properties, one weathered and two sound. C was evaluated in CIE-L ^* a ^* b ^* and CIE-L ^* C ^* _ab h _ab systems, R with R _a and R _z parameters and G using the 20°, 60° and 85° geometries. The weathered granite presents a noticeable colour variation, especially in the b ^* parameter, while the sound ones have a more homogeneous colour. Sound and more textural homogeneous granites have a low surface roughness and high gloss, which are uniformly distributed. The weathered granite shows a higher surface roughness and lower gloss, with scattered distribution. The mineral contacts are the main cause of the surface irregularities. The results show the interdependence between the CRG properties and stress the importance of the polishing process for enhancing the aesthetic characteristics of the granites. CRG properties could be used for quality control in granite processing plants, thus avoiding noticeable differences in the facades of buildings, particularly when weathered granites are used.     

缅甸翡翠的光谱特征及呈色机理

从缅甸翡翠电子探针分析和紫外可见光吸收光谱、激光拉曼光谱、能谱、红外光谱等特征,探讨缅甸翡翠的呈色机理。主要对绿色翡翠和紫色翡翠的呈色机理进行研究。从硬玉呈色、次要矿物呈色和次生色分析得出,绿色翡翠主要由Cr3 致色,紫色翡翠可能是Mn2 致色。     

Effects of salt solutions on the hydro-mechanical behavior of compacted GMZ01 Bentonite

In this study, the effects of salinity of infiltrating solutions on the swelling strain, compressibility, and hydraulic conductivity of compacted GMZ01 Bentonite were investigated. After swelling under vertical load using either distilled water or NaCl solutions with concentrations of 0.1, 0.5 M, and 1 M, laboratory oedometer tests were conducted on the compacted GMZ01 Bentonite. Based on the oedometer test results, hydraulic conductivity was determined using the Casagrande’s method. Results show that the swelling strain of highly compacted GMZ01 Bentonite decreases as the concentration of NaCl solution increases. The compression index C _c ^* increases and then turns to decrease with an increase in the vertical stress or a decrease in the void ratio for different solutions, and the C _c ^* decreases as the concentration of NaCl solution increases. The secondary consolidation coefficient C _α increases linearly with the increase of the compression index C _c ^* . Furthermore, a bi-linear relationship between the swelling index C _s ^* and the secondary consolidation coefficient C _α can be characterized clearly. The hydraulic conductivity increases as the concentration of NaCl solution increases, however, this increase can be prevented if a high confining stress is applied.     

Electronic absorption spectra of Cr3+ ions in natural clinopyroxenes

The polarized (E‖a′, E‖b and E‖c) electronic absorption spectra of five natural chromium-containing clinopyroxenes with compositions close to chromdiopside, omphacite, ureyite-jadeite (12.8% Cr₂O₃), jadeite, and spodumene (hiddenite) were studied. The polarization dependence of the intensities of the Cr³⁺ bands in the clinopyroxene spectra cannot be explained by the selection rules for the point groups C ₂ or C _2v but can be accounted for satisfactorily with the help of the higher order pseudosymmetry model, i.e. with selection rules for the point symmetry group C _3v. The trigonal axis of the pseudosymmetry crystal field forms an angle of 20.5° with the crystallographic direction c in the (010) plane. D _q increases from diopside (1542 cm^?1) through omphacite (1552 cm^?1), jadeite (1574 cm^?1) to spodumene (1592 cm^?1). The parameter B which is a measure of covalency for Cr³⁺-O bonds at M1 sites in clinopyroxene depends on the Cr³⁺ concentration and the cations at M2 sites.     

应用钻石观测仪-红外光谱仪-激光诱导击穿光谱仪鉴定无机材料充填翡翠

通过走访翡翠市场得知存在无机材料充填的翡翠,目前与其相关的研究资料较少,对无机材料充填翡翠缺少鉴定依据.本模拟实验使用水玻璃和硅溶胶这两类无机材料对低档翡翠进行充填以了解其鉴定特征.利用常规宝石学测试、钻石观测仪荧光观察、红外光谱分析(FTIR)、激光诱导击穿光谱分析(LIBS)对无机充填翡翠样品进行测试.结果表明:①...     

Exploring the diverse potentials of <Emphasis Type="Italic">Planococcus</Emphasis> sp. TRC1 for the deconstruction of recalcitrant kraft lignin

Kraft lignin (KL) is the chief contaminant which is responsible for dark coloration, toxicity and high chemical oxygen demand (COD) of paper pulp mill effluent. The present study investigated the diverse potentials of Planococcus sp. TRC1 in the biodegradation of KL. Preliminary evaluation indicated that the strain was able to grow on broad spectrum of lignin-derived compounds, decolorize lignin-mimicking dyes and catabolize substrates of ligninolytic enzymes. Response surface methodology (RSM) was executed to perform the optimization of different process parameters. The results displayed that Planococcus sp. TRC1 could completely utilize 100 mg L^?1 of KL and 78% of 200 mg L^?1 of KL as sole source of carbon with concurrent reduction in COD and color. The biokinetic details of KL biodegradation showed that the values of \(\mu^{*}\), µ _max, \(q^{*}\) and q _max were 0.018 h^?1, 0.01 h^?1, 0.023 g g^?1 h^?1 and 0.05 g g^?1 h^?1, respectively. UV–visible spectrophotometry, SEM and FTIR indicated the significant alterations in the surface morphology, functional groups and chromophores during the course of biodegradation. XRD revealed the emergence of peak signifying the formation of low molecular weight intermediates after bacterial treatment. Considering the environmental impact, bacterial-treated KL illustrated less phytotoxicity using Vigna radiata seed bioassay. These results suggested that Planococcus sp. TRC1 could be a promising strain for the degradation of KL in an ecofriendly way.     

External seismic stability of vertical geosynthetic-reinforced soil walls using pseudo-static method

Analysis of external stability of vertical geosynthetic-reinforced soil (GRS) walls is very important in the seismic prone zone. The scope of this paper is to obtain required minimum reinforcement length, L _min, for external seismic stability of vertical GRS walls by pseudo-static limit equilibrium method. Then, L _min can be calculated to resist sliding, eccentricity, and bearing capacity failure modes. The parameters considered include both horizontal and vertical seismic coefficients (k _h and k _v ), surcharge load (q), wall height (H) and the properties of retained backfill, GRS, and foundation soil. Results show that L _min against sliding failure mode, L _min,S , increases more quickly than that against the other two failure modes with the increase in k _h , q, or unit weight of retained backfill, γ _b , while L _min,S decreases more quickly than that against the other two failure modes with increase in friction angle of retained backfill, ? _b , or unit weight of GRS, γ _r . For the different failure modes, the effect of k _v on L _min is not identical with the change of k _h , and in addition, L _min/H will tend to remain unchanged with the increase in H. In general, L _min against bearing capacity failure mode, L _min,BC, is larger than L _min against the other two failure modes. However, L _min,BC will be less than L _min against eccentricity failure mode, L _min,E , for k _h exceeding 0.35, or friction angle of foundation soil, ? _f , exceeding 37°, and L _min,BC will also be less than L _min,S for friction angle of GRS, ? _r , being no more than 26°.     

High-pressure single-crystal X-ray diffraction study of jadeite and kosmochlor

The crystal structures of natural jadeite, NaAlSi₂O₆, and synthetic kosmochlor, NaCrSi₂O₆, were studied at room temperature, under hydrostatic conditions, up to pressures of 30.4 (1) and 40.2 (1) GPa, respectively, using single-crystal synchrotron X-ray diffraction. Pressure–volume data have been fit to a third-order Birch–Murnaghan equation of state yielding V ₀ = 402.5 (4) Å³, K ₀ = 136 (3) GPa, and K ₀ ^′  = 3.3 (2) for jadeite and V ₀ = 420.0 (3) Å³, K ₀ = 123 (2) GPa and K ₀ ^′  = 3.61 (9) for kosmochlor. Both phases exhibit anisotropic compression with unit-strain axial ratios of 1.00:1.95:2.09 for jadeite at 30.4 (1) GPa and 1:00:2.15:2.43 for kosmochlor at 40.2 (1) GPa. Analysis of procrystal electron density distribution shows that the coordination of Na changes from 6 to 8 between 9.28 (Origlieri et al. in Am Mineral 88:1025–1032, 2003) and 18.5 (1) GPa in kosmochlor, which is also marked by a decrease in unit-strain anisotropy. Na in jadeite remains six-coordinated at 21.5 (1) GPa. Structure refinements indicate a change in the compression mechanism of kosmochlor at about 31 GPa in both the kinking of SiO₄ tetrahedral chains and rate of tetrahedral compression. Below 31 GPa, the O3–O3–O3 chain extension angle and Si tetrahedral volume in kosmochlor decrease linearly with pressure, whereas above 31 GPa the kinking ceases and the rate of Si tetrahedral compression increases by greater than a factor of two. No evidence of phase transitions was observed over the studied pressure ranges.     

Calcification rate and the stable carbon, oxygen, and nitrogen isotopes in the skeleton, host tissue, and zooxanthellae of bleached and recovering Hawaiian corals

We tested the effectiveness of stable isotopes as recorders of physiological changes that occur during coral bleaching and recovery. Montipora capitata and Porites compressa fragments were bleached in outdoor tanks with seawater temperature raised to 30 °C (treatment corals) for one month. Additional fragments were maintained at 27 °C in separate tanks (control corals). After one month, (0 months recovery), buoyant weight was measured and a subset of fragments was frozen. Remaining fragments were returned to the reef for recovery. After 1.5, 4, and 8 months, fragments were collected, measured for buoyant weight, and frozen. Fragments were analyzed for stable carbon and oxygen isotopic compositions of the skeleton (δ¹³C_s; δ¹⁸O_s) and nitrogen and carbon isotopic compositions of the host tissue (δ¹⁵N_h; δ¹³C_h) and zooxanthellae (δ¹⁵N_z; δ¹³C_z). δ¹³C_s decreased immediately after bleaching in M. capitata, but not in P. compressa. δ¹⁸O_s of both species failed to record the warming event. During the remaining months of recovery, δ¹³C_s and δ¹⁸O_s were more enriched in treatment than control corals due to decreases in calcification and metabolic fractionation during that time. Increased δ¹⁵N_h of treatment P. compressa may be due to expelled zooxanthellae during bleaching and recovery. Increased δ¹⁵N_z at 1.5 months in treatment fragments of both species reflects the increased incorporation of dissolved inorganic nitrogen to facilitate mitotic cell division and/or chl a/cell recovery. Changes in δ¹³C_h and δ¹³C_z at 1.5 months in treatment M. capitata indicated a large increase in heterotrophically acquired carbon relative to photosynthetically fixed carbon. We experimentally show that isotopes in coral skeleton, host tissue and zooxanthellae can be used to verify physiological changes during bleaching and recovery, but their use as a proxy for past bleaching events in the skeletal record is limited.