Official Documentation官方文件
Grading System Documents
分級系統文件
Grading Framework評級框架
Five scientifically defined dimensions. One precise, reproducible grade. The complete framework for professional opal evaluation.
五大科學維度，一個精確可重現的評級。專業歐泊評估的完整框架。
Framework Overview框架概覽
| Code | Dimension | Description |
|---|---|---|
| O | Origin Status | Reflects the mining origin and its fundamental influence on quality and physical stability. |
| P | Play of Color | Comprehensively evaluates the geometric morphology, rarity, and proportion of play-of-color patterns. |
| A | Amount of Coverage | Quantifies the percentage of the face-up area exhibiting visible play of color. |
| L | Lucidity | Evaluates body tone depth, transparency, and overall clarity including inclusions and blemishes. |
| S | Spectrum of Color | Evaluates the variety of colors in the play of color, focusing on the presence of the red spectrum. |
| 代號 | 維度名稱 | 評分說明 |
|---|---|---|
| O | 產地等級 | 反映歐泊的礦源產地及其對品質與物理穩定性的根本影響。 |
| P | 變彩綜合評分 | 綜合評估變彩圖案的幾何形態與稀有程度及佔比。 |
| A | 變彩覆蓋率 | 量化正面（Face-up）可見變彩所佔面積之百分比。 |
| L | 清澈度 | 評估底色深度、透明度及整體淨度（包括瑕疵情況）。 |
| S | 色譜分佈 | 評估變彩中所涵蓋的顏色種類，重點考察是否包含紅色光譜。 |
All dimensions scored 0–5. P dimension may retain one decimal place. All assessments conducted face-up under standardized lighting by Accredited OPALS Grading System Gemologists.
所有維度評分範圍 0–5。P 維度可保留一位小數。所有評估均由 OPALS 認證寶石學家在標準照明條件下以正面朝上位置進行。
Dimension One
第一維度
The geographical origin of an opal is the fundamental factor determining its intrinsic quality and physical stability. Different geological environments produce opals with distinct silica water content, sphere packing density, and host rock characteristics — directly influencing Mohs hardness, resistance to crazing, and optical presentation. Australian opals typically possess lower water content and a more stable molecular structure. Lab-grown synthetic opals are classified as O0 and receive no further dimensional scoring.
歐泊的地理產地是決定其內在品質與物理穩定性的根本因素。不同地質環境產出的歐泊，其二氧化矽含水量、微球體排列密度及宿主岩石特性各有差異，直接影響摩氏硬度、抗裂耐久性及變彩呈現效果。澳洲歐泊通常含水量較低，分子結構更為穩定。實驗室培育的合成歐泊歸類為 O0，不進行其餘維度之評級。
| Score | Origin & Type | Characteristics |
|---|---|---|
| 5 | Australian Lightning Ridge (Black Opal); High-quality Queensland Boulder Opal | Exceptional stability and contrast. Lightning Ridge provides characteristic deep body tone (N1–N3). High-quality Boulder Opal bonded to ironstone offers exceptional structural stability. |
| 4 | High-quality Australian Coober Pedy (White/Crystal Opal); Top-tier Mexican Fire Opal (with strong play of color) | High stability and distinctive features. Coober Pedy produces structurally stable White and Crystal Opal. Top-tier Mexican Fire Opal features vivid orange-red body color with strong play of color. |
| 3 | Australian standard-quality opal (White Cliffs, Mintabie, or standard Lightning Ridge/Coober Pedy material) | Standard stability. Inherent physical stability advantages of Australian sedimentary origin, resistant to dehydration crazing. |
| 2 | Ethiopian Welo Mine Opal | Hydrophane characteristics. Majority are hydrophane, readily absorbing moisture with a physical risk of crazing in dry conditions. |
| 1 | Brazilian, Peruvian, or other African opal; All Assembled Natural Opal (Doublets/Triplets) | Emerging origins or composite structure. All assembled opals classified here due to non-solid composite structure. |
| 0 | Lab-grown / Synthetic Opal | Non-geogenic. Artificially grown in laboratory (e.g., Gilson synthetic opals). Category designation only — no further dimensional scoring applied. |
| 評分 | 產地與類別 | 等級特性 |
|---|---|---|
| 5 | 澳洲 Lightning Ridge（黑歐泊）；高品質澳洲昆士蘭礫石歐泊 | 極高穩定性與對比度。Lightning Ridge 具備特有深色底色（N1–N3）。高品質礫石歐泊天然附著於堅硬鐵礦石，結構穩定性極高。 |
| 4 | 澳洲高品質 Coober Pedy（白歐泊/水晶歐泊）；頂級墨西哥火歐泊（需具備強烈變彩） | 高穩定性與特徵表現。Coober Pedy 產出結構穩定的白歐泊與水晶歐泊。頂級墨西哥火歐泊以鮮艷橙紅底色結合強烈變彩為特徵。 |
| 3 | 澳洲一般品質歐泊（含 White Cliffs、Mintabie 或一般品質 Lightning Ridge/Coober Pedy 材料） | 標準穩定性。具備澳洲沉積岩型地質成因的物理穩定優勢，不易因脫水而產生裂紋。 |
| 2 | 衣索比亞 Welo 礦區歐泊 | 水熱性特徵。多數具水熱性，易因環境濕度變化改變外觀，在乾燥環境下具備產生裂紋的物理風險。 |
| 1 | 巴西、秘魯或其他非洲地區歐泊；所有拼合歐泊（Doublets/Triplets） | 新興礦區或複合結構。所有拼合歐泊因非天然整體結構而歸入此等級。 |
| 0 | 實驗室培育/合成歐泊 | 非天然生成。於實驗室環境中人工培育（如 Gilson 合成歐泊）。僅標註類別，不予進行其餘維度評級。 |
Dimension Two
第二維度
Play of Color is the core optical characteristic of opal, arising from the diffraction of visible light by regularly arranged silica spheres. The regularity of sphere arrangement determines pattern clarity and morphology. This system integrates pattern type and distribution ratio into a weighted P-score to objectively reflect the overall geometric quality of play of color.
「變彩」是歐泊核心的光學特徵，源於內部規則排列的微球體對光的衍射效應。微球體排列的規則程度決定了變彩的清晰度與圖案形態。本系統將圖案類型與其分佈比例整合為加權 P 分，客觀反映變彩的整體幾何質素。
| Score | Pattern Type | Characteristics |
|---|---|---|
| 5 | Harlequin / Honeycomb | Clearly defined, sharply bordered mosaic cells in square, diamond, or regular hexagonal arrangements with uniformly sized color patches. |
| 4 | Flagstone / Ribbon / Broad Flash / Straw | Large, irregularly interlocking color patches or wide, flowing color bands delivering strong visual characteristics through large continuous areas. |
| 3 | Floral / Chinese Writing / Palette | Colors distributed in petal-like formations or brushstroke patterns. Lower geometric symmetry; irregular color area boundaries. |
| 2 | Pinfire / Grass | Play of color manifests as very small, point-like or thin fibrous flashes, lacking large continuous color patches. |
| 1 | Moss / Indistinct | Diffuse, cloud-like, or fragmented play of color with poorly defined boundaries and no consistent geometric form. |
| 0 | No Play of Color (Potch) | Completely devoid of play-of-color effect. Produces no optical interference patches or flashes of color. |
| 評分 | 圖案類型 | 特徵詳述 |
|---|---|---|
| 5 | 丑角（Harlequin）/ 蜂巢（Honeycomb） | 具備清晰、邊界銳利的方格狀、菱形或規則六角形蜂巢排列，各色塊大小均勻且分佈規律。 |
| 4 | 旗石 / 絲帶 / 寬闊閃光 / 稻草 | 較大面積的色塊以不規則形態拼接，或呈現如絲帶般寬幅流動的色帶，大面積色塊覆蓋具備強烈視覺特徵。 |
| 3 | 花卉 / 漢字 / 調色板 | 色彩如花瓣散佈或具有書法筆觸感，幾何對稱性較低，色塊邊界不規則。 |
| 2 | 針點（Pinfire）/ 草叢（Grass） | 變彩呈現為極小的點狀或細絲狀閃爍，欠缺大面積連續色塊。 |
| 1 | 苔蘚 / 模糊（Indistinct） | 變彩邊界高度模糊，呈現雲霧狀散佈或細碎不規則形態，無固定幾何形狀。 |
| 0 | 無變彩（Potch） | 完全不具備變彩效應，光線反射或穿透時不會產生光學干涉色塊。 |
Dimension Three
第三維度
Amount of Coverage quantifies the percentage of an opal's face-up area exhibiting visible play of color under standard viewing conditions. Assessment is conducted from a face-up, vertical viewing angle under standardized lighting to estimate the proportion of the visible face displaying play of color.
變彩覆蓋率量化歐泊正面（Face-up）在標準觀察條件下可見變彩所佔的面積百分比。評估應以正面朝上、垂直方向為主要觀察角度，在標準照明條件下估算呈現變彩的面積比例。
| Score | Coverage | Description |
|---|---|---|
| 5 | 95% – 100% | Full Coverage: Virtually the entire face is covered by play of color with negligible non-color areas. |
| 4 | 75% – 94% | Excellent Coverage: Overwhelming majority of the face displays vibrant play of color, with only minor non-color areas. |
| 3 | 40% – 74% | Partial Coverage: Approximately half to three-quarters of the face exhibits play of color. |
| 2 | 10% – 39% | Sparse Coverage: Play of color is scattered and limited in visible area. |
| 1 | Below 10% | Minimal Coverage: Only a very small amount of flash present, or observable only at extreme tilt angles. |
| 0 | 0% | No Play of Color: Face completely lacks play-of-color effect. Classified as common opal (potch). |
| 評分 | 覆蓋率範圍 | 等級描述 |
|---|---|---|
| 5 | 95% – 100% | 極致全滿色：幾乎整個正面均鋪滿變彩，幾乎不存在無變彩區域。 |
| 4 | 75% – 94% | 優質覆蓋：絕大部分正面均有鮮明變彩呈現，僅有少量無變彩區域。 |
| 3 | 40% – 74% | 部分覆蓋：正面約一半至四分之三的區域呈現變彩。 |
| 2 | 10% – 39% | 稀疏閃光：變彩分佈稀疏，可見面積有限。 |
| 1 | 低於 10% | 極微量：正面幾乎不見可見變彩，或僅在特定傾斜角度下才能觀察到極少量閃光。 |
| 0 | 0% | 無變彩：正面完全不具備變彩效應，屬於普通歐泊（Common Opal）。 |
Dimension Four
第四維度
This dimension evaluates the quality of the opal's body tone, transparency, and overall clarity — including natural inclusions, sand spots, and cracks (crazing). For black opal, a darker body tone (closer to N1) elevates the contrast of the play of color. For crystal opal, internal transparency is the primary indicator. Cracks represent a severe negative factor threatening structural integrity and physical durability.
本維度評估歐泊的底色品質、透明度及整體淨度，包括天然包裹體、砂眼或裂紋。對於黑歐泊，越接近純黑（N1）的底色越能提升變彩對比度；對於水晶歐泊，內部透明度是主要指標。裂紋是嚴重影響石材結構完整性的因素。
| Score | Grade | Assessment Criteria |
|---|---|---|
| 5 | Exceptional Clarity | Black Opal: Body tone N1–N3, deep and uniform. Crystal Opal: Fully transparent, no haziness. White Opal: Uniform white body tone, excellent lucidity, no visible blemishes. |
| 4 | Fine Quality | Even body tone with smooth lucidity. No sand spots or cracks visible to the naked eye. Clean and clear visual impression. |
| 3 | Moderate Quality | Minor natural inclusions, sparse sand spots, or slight unevenness of body tone present, but not significantly affecting structural integrity. |
| 2 | Below Average | Noticeable internal haziness, dull surface finish, or numerous sand spots visibly affecting presentation. |
| 1 | Inferior / Flawed | Obvious cracks, dense sand spots, heavy mineral inclusions, or identifiable artificial repair compromising structural integrity. |
| 0 | Structural Failure | Severe crazing with highly unstable structure, or the stone is entirely encased in matrix/potch without lucidity. |
| 評分 | 等級 | 具體評估標準 |
|---|---|---|
| 5 | 極致純淨 | 黑歐泊底色達 N1–N3，均勻無瑕；水晶歐泊完全透明無霧狀感；白歐泊底色潔白均勻，表面清澈度高無可見瑕疵。 |
| 4 | 優質 | 底色均勻飽滿，表面清澈平滑；肉眼不可見任何砂眼或裂紋，整體呈現清晰乾淨的視覺觀感。 |
| 3 | 普通 | 可見輕微天然包裹體、少量分散砂眼或底色輕微不均，但不顯著影響整體結構。 |
| 2 | 渾濁 | 內部存在明顯霧狀感，透明度欠佳；或表面清澈度悶啞；或砂眼數量較多。 |
| 1 | 嚴重瑕疵 | 存在明顯裂痕、大量砂眼、嚴重礦物包裹體或顯著人工修復痕跡，損害結構完整性。 |
| 0 | 結構性崩壞 | 存在嚴重龜裂（Crazing），結構極度不穩定；或石材完全被礦渣包裹且無清澈度。 |
Dimension Five
第五維度
The S dimension replaces reliance on "viewing direction" with an absolute, quantifiable measure: the number and range of colors displayed. The larger the silica sphere diameter, the more capable of diffracting long-wavelength red light (~700 nm). By calculating the number of colors and spectral span displayed, this dimension provides an objective scientific indicator to distinguish opals with different optical performances.
本系統引入「S - 色譜分佈」取代傳統對「觀察方向」的依賴。微球體直徑越大，愈能繞射出長波長的紅光（約 700 nm）。透過計算歐泊能展現的顏色數量與光譜跨度，提供絕對可量化且客觀的科學指標，精確區分不同光學表現的歐泊。
| Score | Spectrum Type | Characteristics |
|---|---|---|
| 5 | Full Spectrum | Simultaneously exhibits 5–7 colors including red, orange, yellow, green, blue, and violet, or possesses a complete spectral span from red to violet. |
| 4 | Multi-color Warm | Possesses 3–4 colors and must include red or orange (long-wavelength warm colors). |
| 3 | Multi-color Cool/Mid | Possesses 3–4 colors but does not include red tones. Composed primarily of yellow, green, blue, and violet. |
| 2 | Dual-color | Only 2 colors observable. Typically green-blue, blue-violet, or green-yellow. |
| 1 | Monochrome | Play of color is present, but only a single color is visible from any angle. |
| 0 | No Play of Color (Potch) | Completely devoid of play-of-color effect. Exhibits only its own body tone. |
| 評分 | 色譜類型 | 具體特徵 |
|---|---|---|
| 5 | 全色譜（Full Spectrum） | 同時呈現紅、橙、黃、綠、藍、紫等 5–7 種顏色，或具備完整的「紅至紫」光譜跨度。 |
| 4 | 多色暖調（Multi-color Warm） | 具備 3–4 種顏色，且必須包含紅色或橙色（長波長暖色）。 |
| 3 | 多色冷/中調（Multi-color Cool/Mid） | 具備 3–4 種顏色，但不含紅色系。主要由黃、綠、藍、紫組成。 |
| 2 | 雙色（Dual-color） | 僅能觀察到 2 種顏色。通常為綠-藍、藍-紫或綠-黃。 |
| 1 | 單色（Monochrome） | 具備變彩效應，但從任何角度觀察均僅呈現單一顏色。 |
| 0 | 無變彩（Potch） | 完全不具備變彩效應，僅呈現單一底色。 |
Practical Example實戰案例
A natural black opal from Lightning Ridge, New South Wales, Australia. Deep and pure body tone (N1–N2), no visible inclusions or cracks to the naked eye. Play-of-color coverage approaches 100%. Spectrum presents a multi-color warm tone inclusive of red and orange. Pattern comprises 20% Broad Flash and 80% Pinfire.
一粒來自澳洲新南威爾士州 Lightning Ridge 的天然黑歐泊，底色深邃純淨（N1–N2），肉眼下無可見瑕疵或裂紋。變彩覆蓋率接近 100%，色譜呈現具備紅色與橙色的「多色暖調」。變彩圖案由 20% 寬闊閃光（Broad Flash）及 80% 針點（Pinfire）組成。
| Dimension | Calculation | Score |
|---|---|---|
| O — Origin | Australian Lightning Ridge Natural Black Opal | O5 |
| P — Play of Color | Broad Flash (score 4) × 20% + Pinfire (score 2) × 80% = 0.8 + 1.6 = 2.4 | P2.4 |
| A — Coverage | Face-up coverage approaching 100% | A5 |
| L — Lucidity | Body tone N1–N2, deep and pure, no naked-eye visible blemishes | L5 |
| S — Spectrum | Red, orange, green, blue — multi-color including long-wavelength warm tones | S4 |
| 維度 | 計算過程 | 評分 |
|---|---|---|
| O — 產地 | 澳洲 Lightning Ridge 天然黑歐泊 | O5 |
| P — 變彩 | 寬闊閃光（4分）× 20% + 針點（2分）× 80% = 0.8 + 1.6 = 2.4 | P2.4 |
| A — 覆蓋率 | 正面覆蓋率接近 100% | A5 |
| L — 清澈度 | 底色 N1–N2，深邃純淨，無肉眼可見瑕疵 | L5 |
| S — 色譜 | 呈現紅、橙、綠、藍等多種色彩，包含長波長暖色 | S4 |
Interactive Tool互動工具
Input values for each dimension to calculate an indicative OPALS grade. For official grading, evaluation must be conducted by an Accredited OPALS Grading System Gemologist.
輸入各維度數值以計算示範性 OPALS 評級。官方評級須由 OPALS 認證寶石學家進行。
Official Documentation官方文件