|
When clear & colorless, this common mineral is known as rock crystal |
quartz
|
$600 |
J |
MINERALOGY |
2025-05-12 |
#9331 |
|
This mineral whose crystals can be used to keep accurate time precedes "crisis" in the history of 1970s Swiss watchmaking |
quartz
|
$800 |
DJ |
MINERALS |
2024-11-13 |
#9203 |
|
This mineral that is used in kitchen countertops could get a minimum of 24 points in Scrabble |
quartz
|
$400 |
DJ |
WAIT JUST A MINERAL! |
2022-10-04 |
#8712 |
|
Thismineral was called krystallos by the ancient Greeks & is primarily silicon dioxide |
quartz
|
$800 |
DJ |
ROCKS & MINERALS |
2022-02-03 |
#8569 |
|
Around 1920 plates of this silicon mineral were first used to control radio frequencies |
quartz
DD
|
$2,000 |
DJ |
ROCKS & MINERALS |
2003-01-01 |
#4223 |
|
Granite is composed mainly of feldspar & this transparent crystalline material |
quartz
|
$600 |
DJ |
GEOLOGY |
2001-07-10 |
#3897 |
|
Amethyst is an example of this mineral, nearly pure silicon dioxide |
quartz
|
$800 |
DJ |
ROCKS & MINERALS |
1996-06-17 |
#2731 |
|
Sandstone grains are made up of mainly feldspar & this mineral |
quartz
|
$800 |
DJ |
ROCKS & MINERALS |
1995-05-08 |
#2471 |
|
Agate, jasper & bloodstone are all forms of this silica mineral |
quartz
|
$1,000 |
DJ |
GEMS & JEWELRY |
1995-02-02 |
#2404 |
|
Of quartz, calcite, or mica, the one which has no cleavage |
quartz
|
$300 |
J |
ROCKS & MINERALS |
1992-02-17 |
#1726 |
|
Granite is made up mainly of feldspar & this mineral which appears as transparent crystals |
quartz
|
$400 |
DJ |
GEOLOGY |
1992-01-22 |
#1708 |
|
This mineral, especially when transparent, is called rock crystal |
quartz
|
$800 |
DJ |
ROCKS & MINERALS |
1991-02-18 |
#1496 |
|
Onyx, jasper & agate are varieties of this mineral |
quartz
|
$800 |
DJ |
GEMS |
1990-10-24 |
#1413 |
|
The Greeks called this mineral "krystallos", which is where we got the word crystal |
quartz
|
$800 |
DJ |
ROCKS & MINERALS |
1989-02-08 |
#1028 |
|
Rock crystal is the clear form of this mineral |
quartz
|
$400 |
DJ |
GEOLOGY |
1988-10-10 |
#941 |