Lets Collect Rocks and Shells

Let's Collect Rocks and Shells

Project Gutenberg's Let's collect rocks & shells, by Shell Oil Company
Copyright laws are changing all over the world. Be sure to check the
copyright laws for your country before downloading or redistributing
this or any other Project Gutenberg eBook.
This header should be the first thing seen when viewing this Project
Gutenberg file. Please do not remove it. Do not change or edit the
header without written permission.
Please read the "legal small print," and other information about the
eBook and Project Gutenberg at the bottom of this file. Included is
important information about your specific rights and restrictions in how
the file may be used. You can also find out about how to make a
donation to Project Gutenberg, and how to get involved.
**Welcome To The World of Free Plain Vanilla Electronic Texts**
**eBooks Readable By Both Humans and By Computers, Since
1971**
*****These eBooks Were Prepared By Thousands of
Volunteers!*****
Title: Let's collect rocks & shells
Author: Shell Oil Company
Release Date: December, 2003 [Etext #4768] [Yes, we are more than
one year ahead of schedule] [This file was first posted on March 15,
2002]
Edition: 10
Language: English

Character set encoding: ASCII
*** START OF THE PROJECT GUTENBERG ETEXT LET'S
COLLECT ROCKS & SHELLS ***

This etext was produced by Justin ([email protected]).

CONTENTS

COLLECTING SEASHELLS SEASHELLS. . .WHAT ARE THEY?
THE SHELL AS AN ARCHITECT LET'S MEET SOME SHELLS
WHERE TO LOOK STARTING A COLLECTION. . .HERE'S HOW
COLLECTING ROCKS ROCKS ARE MADE OF MINERALS MAIN
KINDS OF ROCKS COLLECTING GEMS FOR THE LUCKY FEW

INTRODUCTION

Millions of people throughout the world have found many hours of
pleasure, adventure and education by collecting either rocks or shells.
This booklet won't tell you everything there is to know about rocks and
shells. That would require many large volumes. We only want to
arouse your curiosity about two delightful pastimes that are so broad
and varied that they can lead to a career or a satisfying hobby.
Shell Oil Company's interest in the subjects comes from its history and
the nature of its business. The name--chosen by a company that was
founded years before anyone thought of drilling for oil--comes from the
seashells this company brought from the Orient for use in
mother-of-pearl items such as buttons and knife handles.
Now its world-famous emblem (the Pecten) is recognized by millions
of people in every walk of life. It's on service stations, trucks, buildings,
oil derricks and chemical plants. Even the company's industrial
lubricants are named for shells because shells have the same scientific
names everywhere in the world.
For an oil company, rocks have a special interest. Crude oil is found
not in underground lakes or pools but in the tiny spaces between grains
of sand or in the pores of rocks. Only certain types of rock formations

are favorable to the accumulation of oil. Thus, oilmen need to know
everything they can about the right kind of rocks.
Shell has scientists who work with rocks all day and laboratories filled
with rock, mineral and crystal specimens. We are always learning new
things about them.
The pages that follow provide basic information about two subjects that
can be richly rewarding whether you follow them for profit, as Shell
does, or for pleasure, as millions of people around the world do.

SEASHELLS. . .WHAT ARE THEY?

First, a seashell is one of the 100,000 species of backboneless animals
belonging to the zoological group known as the Mollusca. Mollusks
include not only the familiar clams, scallops and snails, but also the
squids, octopus and Chambered Nautilus. Other "shells" found in the
ocean include those of crabs, lobsters, barnacles and sea urchins.
True molluscan shells come in two main varieties: BIVALVES and
UNIVALVES. Bivalves have two valves, fitting together along a
toothed hinge on one side, and kept closed by means of ADDUCTOR
MUSCLES. Univalves have only one shell, usually coiled, but
sometimes shaped like a cap or miniature volcano. Some marine
univalves can seal themselves inside with an operculum, which covers
the open end of the shell like a trap door. Although shells take on many
different shapes, they are much alike inside. Each has a foot, a
breathing siphon, a tiny brain and heart, and a fleshy mantle which
secretes lime for shell-building. Most true mollusks have eyes, but a
few are blind. Many have teeth, called RADULAE.
Like any other animal, the mollusk generally moves about. It pushes
along on the ocean floor on its foot, or it might swim a little. It lays
millions of eggs and hatches countless baby mollusks. It lives its life in
its shell, lugging it around, snuggling into it when alarmed, burrowing
into mud, fastening itself to a rock and