Opal Rough- 11 g - (6)
03
days
13
hours
46
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23
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Starting bid
€ 1
Reserve price not met
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Selected by Antonio Rapisarda
Holds a master’s in chemistry with 25 years’ experience in minerals consulting.
Estimate € 180 - € 200
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Description from the seller
Lotto composed of 6 Rough Ethiopian Opals
55 Carats - 11Gr
Following is the description for single lots
1) LOTTO 1 ROUGH OPAL 2gr-10Carats
The stone shown in the photo is a rough Ethiopian fire opal (also known as Welo Opal).
Description and Physical Characteristics
* Morphology and Cut: This is a mineral crystal in a rough state (uncut and unpolished), preserving its original free form (rough). The upper part still shows a portion of the clay/gypsum-colored light matrix rock.
* Color and Transparency: The base of the stone body has a warm honey-orange hue, translucent. The most important feature is the optical phenomenon visible at the center: a clear iridescent flash of neon green and yellowish color produced by the light diffraction inside the silica lattice of the stone.
* Weight Conversion: The 2 grams indicated correspond exactly to 10 carats (ct), the standard unit of measure used in the gemstone market.
Lotto 2 rough opal 4Gr - 20 Carats
This specimen is a fragment of rough noble opal on rocky matrix (Boulder Opal), presumably of Australian origin.
The value of this piece is higher than the previous ones due to the doubled weight (4g equals 20 carats) and the presence of rarer colors (purple/violet increases the value compared to just green).
Description and Visual Characteristics
* Morphology and Structure: This is a natural rough sample. The gem is set within a massive host rock (matrix) of dark brown, clayey and ferruginous color.
* Play-of-Color: Compared to the previous photo of the same piece, this closer, better-lit shot shows greater potential. In the upper right portion there is a vivid neon green and purple/violet iridescent flash.
* The Opal Body: The central vein running through the rock has a milky, semitranslucent texture, with gray-blue zones forming the base for the surface iridescence.
Description and Visual Characteristics
* Morphology and Structure: This is a natural rough sample. The gem is set within a massive host rock (matrix) of dark brown, clayey and ferruginous color.
* Play-of-Color: Compared to the previous photo of the same piece, this closer, better-lit shot shows greater potential. In the upper right portion there is a vivid iridescent flash of neon green and purple/violet.
* The Opal Body: The central vein crossing the rock has a milky and semitranslucent consistency, with gray-blue zones forming the base for the surface iridescence.
Lotto 3 rough Opal 2Gr 10 Ct.
This specimen is an exceptional fragment of noble hydrophane fire opal rough, of Ethiopian (Welo) origin.
It is the most valuable piece qualitatively among those shown so far.
Gemmological Description and Characteristics
* Play-of-Color: The stone shows a full and vivid spectrum. Under this direct light, intense multicolor iridescent flashes are clearly visible: fire red, neon orange, bright green, and blue specks in the lower portion.
* Body Tone: The opal body has a highly translucent crystal base with amber and honey tones, typical of African fire opals with a glassy texture.
* Matrix Presence: The gray, porous host rock is confined almost entirely to the right edge and bottom. This means that nearly all of the weight is noble opal usable.
* Size/Weight Ratio: 2 grams equal 10 carats (ct). The measurements (1.8 cm height and less than 1 cm thickness and width) indicate an elongated shard-like shape.
Lotto 4 rough Opal 1Gr - 5 Ct.
This specimen is a fragment of white crystalline noble opal rough (most likely an Ethiopian Welo Opal).
Gemmological Description and Characteristics
* Play-of-Color: The stone shows a beautiful color contrast. Prominent electric neon green flashes distributed in patches over the entire surface, accompanied by a distinct orange/reddish patch on the left side and yellow reflections on the right.
* Body Tone: Unlike the previous pieces with amber base, this sample has a milky and semitranslucent base, defined in gemology as white opal or clear crystal.
* Structure and Matrix: The piece is in natural rough state. It features a sandy beige host rock section confined to the back and the upper right edge, while the main body is composed entirely of noble opal.
* Size/Weight: 1 gram equals exactly 5 carats (ct). The dimensions indicate a compact and slightly curved shard.
Lotto 5 Opal -1 Gr. 5Ct.
This specimen is a small shard of crystalline noble opal rough (Welo type, origin Ethiopia). 1 gram (5 carats).
Gemmological Description and Characteristics
* Play-of-Color: Despite the small size, the stone shows a beautiful concentrated iridescence. A vivid neon green flash appears in the lower portion, accompanied by blue electric splinters and orange hues on the honeyed base.
* Body Tone: The base has a glassy, translucent, and crystalline texture (crystal opal) varying from transparent to pale amber yellow at the center of the fragment.
* Structure and Matrix: The piece is completely natural rough. On the upper left edge there is a small crust of dark brown host rock, while the right portion ends in a very thin and transparent pointed form.
* Size/Weight: The weight of 1 gram equals exactly 5 carats (ct). The shape is very irregular, jagged, and shard-like.
Market Value Analysis
The price is slightly lower than the 1-gram piece due to its geometry:
* Jagged Shape: The shard-like structure and the presence of sharp edges limit workable options. A potential cabochon cut would involve a very high material loss, making it ideal mainly as a rough or educational collectible.
* Vibrancy of Green-Blue: The color quality remains very high; the blue and green reflections are saturated and respond well even in suboptimal lighting, keeping the piece interesting for mineral enthusiasts.
Lotto 6 Opal 5 Ct
This specimen is a fragment of noble transparent crystal opal rough on matrix, clearly of Ethiopian (Welo) origin.
Gemmological Description and Characteristics
* Play-of-Color: On the predominantly glassy base, delicate but diffuse iridescent spots are visible. A blue electric splinter at the bottom and mild orange and green reflections in the central section stand out.
* Body Tone: The opal body is of crystal transparent type (crystal opal), almost colorless and ice-like, unlike the darker amber bases of the previous pieces.
* Matrix and Structure: The ferruginous dark brown host rock concentrates at the upper vertex, creating a distinct cap over the crystal. The structure shows several natural fractures and internal cleavage lines typical of rough material.
* Proportions: The weight of 1 gram (5 carats) forms a nearly cubic and compact shape, given the nearly identical measurements: width 1.03 cm, height 1 cm, and depth 9 mm.
Total Lot of 6 Ethiopian Opals - 11 grams - total 55 Carats
A total weight of 11 grams of Ethiopian opals corresponds exactly to 55 carats.
The overall commercial value for this entire rough lot is estimated between 170 and 310 euros, calculated by summing the individual pieces examined so far and considering the premium value of the higher-quality pieces with red and orange reflections.
View the images for a correct assessment.
Ships with protective packaging and tracking
Lotto composed of 6 Rough Ethiopian Opals
55 Carats - 11Gr
Following is the description for single lots
1) LOTTO 1 ROUGH OPAL 2gr-10Carats
The stone shown in the photo is a rough Ethiopian fire opal (also known as Welo Opal).
Description and Physical Characteristics
* Morphology and Cut: This is a mineral crystal in a rough state (uncut and unpolished), preserving its original free form (rough). The upper part still shows a portion of the clay/gypsum-colored light matrix rock.
* Color and Transparency: The base of the stone body has a warm honey-orange hue, translucent. The most important feature is the optical phenomenon visible at the center: a clear iridescent flash of neon green and yellowish color produced by the light diffraction inside the silica lattice of the stone.
* Weight Conversion: The 2 grams indicated correspond exactly to 10 carats (ct), the standard unit of measure used in the gemstone market.
Lotto 2 rough opal 4Gr - 20 Carats
This specimen is a fragment of rough noble opal on rocky matrix (Boulder Opal), presumably of Australian origin.
The value of this piece is higher than the previous ones due to the doubled weight (4g equals 20 carats) and the presence of rarer colors (purple/violet increases the value compared to just green).
Description and Visual Characteristics
* Morphology and Structure: This is a natural rough sample. The gem is set within a massive host rock (matrix) of dark brown, clayey and ferruginous color.
* Play-of-Color: Compared to the previous photo of the same piece, this closer, better-lit shot shows greater potential. In the upper right portion there is a vivid neon green and purple/violet iridescent flash.
* The Opal Body: The central vein running through the rock has a milky, semitranslucent texture, with gray-blue zones forming the base for the surface iridescence.
Description and Visual Characteristics
* Morphology and Structure: This is a natural rough sample. The gem is set within a massive host rock (matrix) of dark brown, clayey and ferruginous color.
* Play-of-Color: Compared to the previous photo of the same piece, this closer, better-lit shot shows greater potential. In the upper right portion there is a vivid iridescent flash of neon green and purple/violet.
* The Opal Body: The central vein crossing the rock has a milky and semitranslucent consistency, with gray-blue zones forming the base for the surface iridescence.
Lotto 3 rough Opal 2Gr 10 Ct.
This specimen is an exceptional fragment of noble hydrophane fire opal rough, of Ethiopian (Welo) origin.
It is the most valuable piece qualitatively among those shown so far.
Gemmological Description and Characteristics
* Play-of-Color: The stone shows a full and vivid spectrum. Under this direct light, intense multicolor iridescent flashes are clearly visible: fire red, neon orange, bright green, and blue specks in the lower portion.
* Body Tone: The opal body has a highly translucent crystal base with amber and honey tones, typical of African fire opals with a glassy texture.
* Matrix Presence: The gray, porous host rock is confined almost entirely to the right edge and bottom. This means that nearly all of the weight is noble opal usable.
* Size/Weight Ratio: 2 grams equal 10 carats (ct). The measurements (1.8 cm height and less than 1 cm thickness and width) indicate an elongated shard-like shape.
Lotto 4 rough Opal 1Gr - 5 Ct.
This specimen is a fragment of white crystalline noble opal rough (most likely an Ethiopian Welo Opal).
Gemmological Description and Characteristics
* Play-of-Color: The stone shows a beautiful color contrast. Prominent electric neon green flashes distributed in patches over the entire surface, accompanied by a distinct orange/reddish patch on the left side and yellow reflections on the right.
* Body Tone: Unlike the previous pieces with amber base, this sample has a milky and semitranslucent base, defined in gemology as white opal or clear crystal.
* Structure and Matrix: The piece is in natural rough state. It features a sandy beige host rock section confined to the back and the upper right edge, while the main body is composed entirely of noble opal.
* Size/Weight: 1 gram equals exactly 5 carats (ct). The dimensions indicate a compact and slightly curved shard.
Lotto 5 Opal -1 Gr. 5Ct.
This specimen is a small shard of crystalline noble opal rough (Welo type, origin Ethiopia). 1 gram (5 carats).
Gemmological Description and Characteristics
* Play-of-Color: Despite the small size, the stone shows a beautiful concentrated iridescence. A vivid neon green flash appears in the lower portion, accompanied by blue electric splinters and orange hues on the honeyed base.
* Body Tone: The base has a glassy, translucent, and crystalline texture (crystal opal) varying from transparent to pale amber yellow at the center of the fragment.
* Structure and Matrix: The piece is completely natural rough. On the upper left edge there is a small crust of dark brown host rock, while the right portion ends in a very thin and transparent pointed form.
* Size/Weight: The weight of 1 gram equals exactly 5 carats (ct). The shape is very irregular, jagged, and shard-like.
Market Value Analysis
The price is slightly lower than the 1-gram piece due to its geometry:
* Jagged Shape: The shard-like structure and the presence of sharp edges limit workable options. A potential cabochon cut would involve a very high material loss, making it ideal mainly as a rough or educational collectible.
* Vibrancy of Green-Blue: The color quality remains very high; the blue and green reflections are saturated and respond well even in suboptimal lighting, keeping the piece interesting for mineral enthusiasts.
Lotto 6 Opal 5 Ct
This specimen is a fragment of noble transparent crystal opal rough on matrix, clearly of Ethiopian (Welo) origin.
Gemmological Description and Characteristics
* Play-of-Color: On the predominantly glassy base, delicate but diffuse iridescent spots are visible. A blue electric splinter at the bottom and mild orange and green reflections in the central section stand out.
* Body Tone: The opal body is of crystal transparent type (crystal opal), almost colorless and ice-like, unlike the darker amber bases of the previous pieces.
* Matrix and Structure: The ferruginous dark brown host rock concentrates at the upper vertex, creating a distinct cap over the crystal. The structure shows several natural fractures and internal cleavage lines typical of rough material.
* Proportions: The weight of 1 gram (5 carats) forms a nearly cubic and compact shape, given the nearly identical measurements: width 1.03 cm, height 1 cm, and depth 9 mm.
Total Lot of 6 Ethiopian Opals - 11 grams - total 55 Carats
A total weight of 11 grams of Ethiopian opals corresponds exactly to 55 carats.
The overall commercial value for this entire rough lot is estimated between 170 and 310 euros, calculated by summing the individual pieces examined so far and considering the premium value of the higher-quality pieces with red and orange reflections.
View the images for a correct assessment.
Ships with protective packaging and tracking
Details
Number of objects
6
Main mineral
Opal
Mineral form
Rough
Supplement
55 carats
Weight
11 g
Origin (region/city)
Italy
Country of origin
Ethiopia
Sold by
Disclaimer
It is believed that certain gemstones and minerals have beneficial health and spiritual properties. However, using or wearing gemstones or minerals does not mean that you can treat, cure or prevent any disease. Please consult your health care professional for information on health care issues and do not stop any medications or courses of treatment, without first consulting your health care professional. The use of gemstones or minerals as a wellness therapy is one of personal choice. While stones or crystals have been used historically to relieve or prevent symptoms, the objects sold on our website offer no guarantee of results. Therefore, Catawiki cannot guarantee or be held liable for the effectiveness of these objects sold herein.
It is believed that certain gemstones and minerals have beneficial health and spiritual properties. However, using or wearing gemstones or minerals does not mean that you can treat, cure or prevent any disease. Please consult your health care professional for information on health care issues and do not stop any medications or courses of treatment, without first consulting your health care professional. The use of gemstones or minerals as a wellness therapy is one of personal choice. While stones or crystals have been used historically to relieve or prevent symptoms, the objects sold on our website offer no guarantee of results. Therefore, Catawiki cannot guarantee or be held liable for the effectiveness of these objects sold herein.
