ORTHOCERAS ANCIENT FOSSIL 105 CTS [MGW986 ]

Item Information

Dimensions (mm) 0 x 0 x 0mm
Weight (carats) 0 carats

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 .

 

orthoceras drawing

WEIGHT: 105 CTS APP

SIZE: 67 X 18 X 11 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

 

 

All Feedback

Recent Customer Feedback

closed

1 bid placed so far
$17.00 lam5769
25th Mar 2014 8:04am PDT
Add to Watch List Ask a Question * All prices in USD

Audit Information

This auction has not been audited by a Gemstone Sheriff

Request Audit

Pricing & Details

Bid Increment $1.00
Starting Bid $17.00
Auction ID 34699
Watchers 0 watching
Viewed 366 times
Starts 20th Mar 2014 8:22am PDT
Ends 25th Mar 2014 8:18am PDT

Shipping & Insurance

Provider Shipping Transit
FedEx $25.00 5 Days
Standard Shipping $4.00 21 Days
Shipping Insurance all providers $7.00 (optional)

Seller Details

Visit mineralgemworld Store Add to Favourites