magnetized gem

"C Ryman" schreef in...
Does Magnetite look the same as Hematite?
I have round Hematite beads that are not attacked to magnets. The square
beads look the same as the round but stick to my jewelry chest magnet. I
don't wear the square ones because they seem to cut through the coated wire
thread pretty quick.


Magnetite and hematite are look-alikes!

Precisely 5 minutes ago I found a nice way (apart from magnetism) to make the
distinction (based on
the very limited amount of samples in my collection, 1 hematite, 1 hematine and
two magnetites).

Take an electrical multimeter capable of measuring resistances.
Press the measuring tips close to another on the surface of the stone.
Hematite and hematine gave a resistance 2000 K-Ohm (out of the range of my
meter)
The two magnetites gave a resistance of zero Ohm, so they seem to be perfect
electrical conductors!

I would appreciate it very much if someone who has these stones in his
collection could repeat this
experiment!!


Groeten,

Jaap

Hematine which is used as a imitation of Hematite is attracted to a
hand magnet and can be distinguished from Hematite which is not
attracted.
Robert Webster - GEMS THIRD EDITION pp. 779 - 780

Webster gives a list of other gemstones which have magnetic properties
but which must be measured with a balance using the formula

PULL = ( MAGNETIC LOSS X 100 / SQUARE ROOT OF WEIGHT ) In Miligrams.

Gemstones containing both Iron and Manganese are susceptible to being
magnetic.

Other gemstones might be considered under the heading of Magnetic
Gemstones.

They are Siderite ( Nickle Iron Metorites ) which can be worked like
gemstones
even though they are metal .
And Star Diopside which is magnetic enough that it can be picked up
with a
good magnet. Magnetism is in fact one of its tests.

I have found that a small compass shaped like a ball floating in
liquid is
a good diagonistic tool.

ROBB