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ORTHOCERAS ANCIENT FOSSIL 75 CTS [MGW971 ]
- SKU
- Dimensions (mm)
- x x mm
- Weight (cts)
- Colours
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Orthoceras
Orthoceras was a ancient mollusk that lived more than 400 million years ago. The name means straight horn, referring to the characteristic long, straight, conical shell. The preserved shell is all that remains of this ancestor of our modern-day squid.
THIS SPECIMEN IS VERY WELL POLISHED .
WEIGHT: 75 CTS APP
SIZE: 65 X 19 X 9 MM APP
The soft body lived in the last open-ended segment at the large end of the conical shell. As the body grew and the housing segment became too small, a dividing wall, called the septa, grew to separate the old “home chamber” from the new one. The differences in the composition of these shell parts allowed for differences in fossilization so the parts can be seen.
The siphuncle is a tube that runs the entire length of the shell, through each of the chambers. This tube had two functions. Once filled with water, the nautiloid could force the water out, propelling itself backward with a kind of jet propulsion. By releasing the water and leaving air space, the tube could serve as a bouyancy device allowing the animal to rise and lower itself to different depths.
These straight shelled nautiloids ranged in size from less than a centimeter to more than 14 feet long!
AS WITH ALL OUR STOCK YOU MAY RETURN IT FOR A FULL REFUND IF NOT PLEASED PROVIVED IT IS NOT TOUCHED IN ANY WAY.
| Type 1 Gemstones |
| The following gemstones are typically inclusion free, even minor inclusions detract from their value. |
| Diamond, Amethyst, Beryls(Aquamarine,Morganite), Citrine, Smoky Quartz, topaz, Chrysoberyl, Kunzite, Tanzanite, green Tourmaline, and Blue Zircon |
| IF | Internally flawless under extreme magnification (Very rare) |
| F | Flawless |
| VVS | Minute inclusions under 10x; invisible to the unaided eye |
| VS | Minor inclusions under 10x; usually invisible to the unaided eye |
| SI1 | Noticeable inclusions under 10x; usually visible to the unaided eye |
| SI2 | Noticeable inclusions under 10x; usually quite visible to the unaided eye |
| I1 | prominent- moderate affect on appearance or durability |
| I2 | prominent - severe affect on appearance or durability |
| I3 | prominent- severe affect on beauty, transparency or durability |
| Type 2 Gemstones |
| Gemstones that normally have small inclusions that do not detract from value. |
| Alexandrite, Andalusite, Iolite, Peridot, Rhodolite, Ruby, Sapphire, Spinel, Tourmaline, Garnet, Amethyst, Red Zircon, Tsavorite; Blue, Orange, Purple, Fluorite.Yellow and Parti-colored Tourmaline |
| F | Flawless |
| VVS | Minor inclusions under 10x; usually invisible to the unaided eye |
| VS | Noticeable inclusions under 10x; often invisible to the unaided eye |
| SI1 | Obvious inclusions under 10x; visible to the unaided eye |
| SI2 | Obvious inclusions under 10x; very apparent to the unaided eye |
| I1 | prominent - moderate affect on appearance or durability |
| I2 | prominent - severe affect on appearance or durability |
| I3 | prominent - severe affect on beauty, transparency or durability |
- SKU
- Dimensions (mm)
- x x mm
- Weight (cts)
- Colours
-
Orthoceras
Orthoceras was a ancient mollusk that lived more than 400 million years ago. The name means straight horn, referring to the characteristic long, straight, conical shell. The preserved shell is all that remains of this ancestor of our modern-day squid.
THIS SPECIMEN IS VERY WELL POLISHED .
WEIGHT: 75 CTS APP
SIZE: 65 X 19 X 9 MM APP
The soft body lived in the last open-ended segment at the large end of the conical shell. As the body grew and the housing segment became too small, a dividing wall, called the septa, grew to separate the old “home chamber” from the new one. The differences in the composition of these shell parts allowed for differences in fossilization so the parts can be seen.
The siphuncle is a tube that runs the entire length of the shell, through each of the chambers. This tube had two functions. Once filled with water, the nautiloid could force the water out, propelling itself backward with a kind of jet propulsion. By releasing the water and leaving air space, the tube could serve as a bouyancy device allowing the animal to rise and lower itself to different depths.
These straight shelled nautiloids ranged in size from less than a centimeter to more than 14 feet long!
AS WITH ALL OUR STOCK YOU MAY RETURN IT FOR A FULL REFUND IF NOT PLEASED PROVIVED IT IS NOT TOUCHED IN ANY WAY.
| Type 1 Gemstones |
| The following gemstones are typically inclusion free, even minor inclusions detract from their value. |
| Diamond, Amethyst, Beryls(Aquamarine,Morganite), Citrine, Smoky Quartz, topaz, Chrysoberyl, Kunzite, Tanzanite, green Tourmaline, and Blue Zircon |
| IF | Internally flawless under extreme magnification (Very rare) |
| F | Flawless |
| VVS | Minute inclusions under 10x; invisible to the unaided eye |
| VS | Minor inclusions under 10x; usually invisible to the unaided eye |
| SI1 | Noticeable inclusions under 10x; usually visible to the unaided eye |
| SI2 | Noticeable inclusions under 10x; usually quite visible to the unaided eye |
| I1 | prominent- moderate affect on appearance or durability |
| I2 | prominent - severe affect on appearance or durability |
| I3 | prominent- severe affect on beauty, transparency or durability |
| Type 2 Gemstones |
| Gemstones that normally have small inclusions that do not detract from value. |
| Alexandrite, Andalusite, Iolite, Peridot, Rhodolite, Ruby, Sapphire, Spinel, Tourmaline, Garnet, Amethyst, Red Zircon, Tsavorite; Blue, Orange, Purple, Fluorite.Yellow and Parti-colored Tourmaline |
| F | Flawless |
| VVS | Minor inclusions under 10x; usually invisible to the unaided eye |
| VS | Noticeable inclusions under 10x; often invisible to the unaided eye |
| SI1 | Obvious inclusions under 10x; visible to the unaided eye |
| SI2 | Obvious inclusions under 10x; very apparent to the unaided eye |
| I1 | prominent - moderate affect on appearance or durability |
| I2 | prominent - severe affect on appearance or durability |
| I3 | prominent - severe affect on beauty, transparency or durability |
| Shipping provider | Shipping to Australia | Shipping to rest of world |
|---|---|---|
| FedEx | $12.00 / 3 days | $39.00 / 10 days |
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Australia
FedEx is discounted to $12.00 on orders with 2 or more items
Rest of the world
FedEx is discounted to $39.00 on orders with 2 or more items
|
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| Registered Shipping | $9.00 / 7 days | $16.00 / 21 days |
|
Australia
Registered Shipping is discounted to $9.00 on orders with 2 or more items
Rest of the world
Registered Shipping is discounted to $16.00 on orders with 2 or more items
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PositiveBeautiful agate piece , and as always fast efficient service from Sedagems
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Positive
Nice
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Positive
Gorgeous stones, very happy
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Positive
Gorgeous stone, very happy
![22.9CTS VARASCITE 'SPIDER WEB' AUSTRALIA [MGW 4616]](https://liveplatforms-production.b-cdn.net/tenants/gr/uploads/images/490000-494999/490866/55236df10a48f.JPG?width=480&aspect_ratio=1001%3A1000)
