Opal Rough- 11 g - (6)
06
days
04
hours
33
minutes
45
seconds
Starting bid
€ 1
Reserve price not met
Expert
Selected by Antonio Rapisarda
Holds a master’s in chemistry with 25 years’ experience in minerals consulting.
Estimate € 180 - € 200
No bids placed
Catawiki Buyer Protection
Your payment’s safe with us until you receive your object.View details
Trustpilot 4.4 | 142734 reviews
Rated Excellent on Trustpilot.
Lot of six Ethiopian rough opals, total weight 11 g, 55 carats.
AI-assisted summary
Description from the seller
Lotto composed of 6 Rough Ethiopian Opals
55 Carats - 11g
Follow description for individual lots
1) LOTTO 1 ROUGH OPAL 2g-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: It is a mineral crystal in the rough state (untreated and unpolished), retaining its original free form (rough). The upper part still shows a portion of the light-colored clay/gypsum matrix rock.
* Color and Transparency: The base of the stone’s body has a warm orange-honey tone that is translucent. The most important aspect is the optical phenomenon visible at the center: a clear iridescent flash of neon green and yellow generated by light diffraction within the silica lattice of the stone.
* Weight Conversion: The indicated 2 grams exactly correspond to 10 carats (ct), the standard unit of measure used in the gemstone market.
Lot 2 rough opal 4Gr - 20 Carats
This specimen is a fragment of noble rough 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 its value compared to only green).
Description and Visual Features
* Morphology and Structure: It is a natural rough specimen. The gem is set within a massive mother 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. On the upper right portion stands a vivid iridescent flash of neon green and purple/purple.
* The Opal Body: The central vein running through the rock has a milky and semi-translucent consistency, with gray-blue zones that form the base for the surface iridescence.
Description and Visual Features
* Morphology and Structure: It is a natural rough specimen. The gem is set within a massive mother rock (matrix) of dark brown, clay-like and ferruginous color.
* Play-of-Color: Compared to the previous photo of the same piece, this closer, better-lit shot shows greater potential. On the upper right portion stands a vivid iridescent flash of neon green and purple/purple.
* The Opal Body: The central vein across the rock has a milky and semi-glossy texture, with gray-blue areas forming the base for surface iridescence.
Lotto 3 Rough Opal 2Gr 10 Ct.
This specimen is an exceptional fragment of noble hydrofane fire opal rough, of Ethiopian (Welo) origin.
It is the highest quality piece among those shown so far.
Gemmological Description and Characteristics
* Play-of-Color: The stone displays a full, vivid spectrum. Under direct lighting, intense multicolored iridescent flashes are clearly visible: fire red, neon orange, bright green and bluish specks at the bottom.
* Body Tone: The opal body has a highly translucent crystal base with amber and honey tones, typical of African fire opals with a glassy weave.
* Matrix Presence: The grayish, porous host rock is confined almost entirely to the right edge and bottom. This means the vast majority of the weight is usable noble opal.
* Size/Weight Ratio: 2 grams correspond to 10 carats (ct). The measurements (1.8 cm height and less than 1 cm thick and wide) indicate an elongated shard form.
Lotto 4 Rough Opal 1Gr - 5 Ct.
This specimen is a fragment of white crystalline noble opal rough (very likely a Welo Opal of Ethiopian origin).
Gemmological Description and Characteristics
* Play-of-Color: The stone shows a beautiful color contrast. Intense neon green electric flashes are distributed in spots across the surface, accompanied by a definite 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 semi-glossy base, defined in gemmology as white opal or clear crystal.
* Structure and Matrix: The piece is natural rough. A sandy, beige mother rock portion is 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 arched shard.
Lotto 5 Opal -1 Gr. 5Ct.
This specimen is a small shard of crystal noble opal rough (Welo type, Ethiopian origin). 1 gram (5 carats).
Gemmological Description and Characteristics
* Play-of-Color: Despite the small size, the stone shows a beautiful iridescence concentrated. A vivid neon green flash is visible at the lower part, accompanied by blue electric specks and orange hues on the honey-colored 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 entirely natural rough. On the upper left edge there is a small crust of dark brown mother rock, while the right portion ends in a very thin, transparent tip.
* Size/Weight: 1 gram equals exactly 5 carats (ct). The shape is very irregular, jagged, and splintered.
Value Market Analysis
The price is slightly lower than the 1-gram piece due to its geometry:
* Jagged Shape: The shard-like thin structure and sharp edges limit workability. A potential cabochon cut would involve a very high material loss, making it ideal mainly as a raw or educational collection piece.
* Color Vibrancy (Green-Blue): The color quality remains very high; blue and green reflections are saturated and respond well even in suboptimal lighting, keeping the piece interesting for mineral enthusiasts.
Lotto 6 OPALE 5 Ct
This specimen is a fragment of noble crystal opal rough on matrix, clearly of Ethiopian origin (Welo).
Gemmological Description and Characteristics
* Play-of-Color: On the mainly glassy base, delicate but widespread iridescent points are visible. A blue electric speck at the bottom and light orange and green reflections in the central section stand out.
* Body Tone: The opal body is a transparent crystal opal, almost colorless and ice-like, different from the previous pieces with a more amber background.
* Matrix and Structure: The ferruginous dark brown rock is concentrated at the top vertex, creating a clear cap over the crystal. The structure shows several natural fractures and internal cleavage lines typical of rough material extracted in bulk.
* Proportions: The weight of 1 gram (5 carats) develops over a nearly cubic and compact form, given the almost identical measurements across width (1.03 cm), height (1 cm), and depth (9 mm).
Total Lot of the 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 ranges between 170 and 310 euros, calculated by summing the individual pieces examined so far and considering the premium value of higher-quality pieces with red and orange reflections.
Look at the images for proper assessment.
Shipping is with protective packaging and tracking
Lotto composed of 6 Rough Ethiopian Opals
55 Carats - 11g
Follow description for individual lots
1) LOTTO 1 ROUGH OPAL 2g-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: It is a mineral crystal in the rough state (untreated and unpolished), retaining its original free form (rough). The upper part still shows a portion of the light-colored clay/gypsum matrix rock.
* Color and Transparency: The base of the stone’s body has a warm orange-honey tone that is translucent. The most important aspect is the optical phenomenon visible at the center: a clear iridescent flash of neon green and yellow generated by light diffraction within the silica lattice of the stone.
* Weight Conversion: The indicated 2 grams exactly correspond to 10 carats (ct), the standard unit of measure used in the gemstone market.
Lot 2 rough opal 4Gr - 20 Carats
This specimen is a fragment of noble rough 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 its value compared to only green).
Description and Visual Features
* Morphology and Structure: It is a natural rough specimen. The gem is set within a massive mother 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. On the upper right portion stands a vivid iridescent flash of neon green and purple/purple.
* The Opal Body: The central vein running through the rock has a milky and semi-translucent consistency, with gray-blue zones that form the base for the surface iridescence.
Description and Visual Features
* Morphology and Structure: It is a natural rough specimen. The gem is set within a massive mother rock (matrix) of dark brown, clay-like and ferruginous color.
* Play-of-Color: Compared to the previous photo of the same piece, this closer, better-lit shot shows greater potential. On the upper right portion stands a vivid iridescent flash of neon green and purple/purple.
* The Opal Body: The central vein across the rock has a milky and semi-glossy texture, with gray-blue areas forming the base for surface iridescence.
Lotto 3 Rough Opal 2Gr 10 Ct.
This specimen is an exceptional fragment of noble hydrofane fire opal rough, of Ethiopian (Welo) origin.
It is the highest quality piece among those shown so far.
Gemmological Description and Characteristics
* Play-of-Color: The stone displays a full, vivid spectrum. Under direct lighting, intense multicolored iridescent flashes are clearly visible: fire red, neon orange, bright green and bluish specks at the bottom.
* Body Tone: The opal body has a highly translucent crystal base with amber and honey tones, typical of African fire opals with a glassy weave.
* Matrix Presence: The grayish, porous host rock is confined almost entirely to the right edge and bottom. This means the vast majority of the weight is usable noble opal.
* Size/Weight Ratio: 2 grams correspond to 10 carats (ct). The measurements (1.8 cm height and less than 1 cm thick and wide) indicate an elongated shard form.
Lotto 4 Rough Opal 1Gr - 5 Ct.
This specimen is a fragment of white crystalline noble opal rough (very likely a Welo Opal of Ethiopian origin).
Gemmological Description and Characteristics
* Play-of-Color: The stone shows a beautiful color contrast. Intense neon green electric flashes are distributed in spots across the surface, accompanied by a definite 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 semi-glossy base, defined in gemmology as white opal or clear crystal.
* Structure and Matrix: The piece is natural rough. A sandy, beige mother rock portion is 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 arched shard.
Lotto 5 Opal -1 Gr. 5Ct.
This specimen is a small shard of crystal noble opal rough (Welo type, Ethiopian origin). 1 gram (5 carats).
Gemmological Description and Characteristics
* Play-of-Color: Despite the small size, the stone shows a beautiful iridescence concentrated. A vivid neon green flash is visible at the lower part, accompanied by blue electric specks and orange hues on the honey-colored 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 entirely natural rough. On the upper left edge there is a small crust of dark brown mother rock, while the right portion ends in a very thin, transparent tip.
* Size/Weight: 1 gram equals exactly 5 carats (ct). The shape is very irregular, jagged, and splintered.
Value Market Analysis
The price is slightly lower than the 1-gram piece due to its geometry:
* Jagged Shape: The shard-like thin structure and sharp edges limit workability. A potential cabochon cut would involve a very high material loss, making it ideal mainly as a raw or educational collection piece.
* Color Vibrancy (Green-Blue): The color quality remains very high; blue and green reflections are saturated and respond well even in suboptimal lighting, keeping the piece interesting for mineral enthusiasts.
Lotto 6 OPALE 5 Ct
This specimen is a fragment of noble crystal opal rough on matrix, clearly of Ethiopian origin (Welo).
Gemmological Description and Characteristics
* Play-of-Color: On the mainly glassy base, delicate but widespread iridescent points are visible. A blue electric speck at the bottom and light orange and green reflections in the central section stand out.
* Body Tone: The opal body is a transparent crystal opal, almost colorless and ice-like, different from the previous pieces with a more amber background.
* Matrix and Structure: The ferruginous dark brown rock is concentrated at the top vertex, creating a clear cap over the crystal. The structure shows several natural fractures and internal cleavage lines typical of rough material extracted in bulk.
* Proportions: The weight of 1 gram (5 carats) develops over a nearly cubic and compact form, given the almost identical measurements across width (1.03 cm), height (1 cm), and depth (9 mm).
Total Lot of the 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 ranges between 170 and 310 euros, calculated by summing the individual pieces examined so far and considering the premium value of higher-quality pieces with red and orange reflections.
Look at the images for proper assessment.
Shipping is 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.
