red spinel, its history, origin and about spine'ls 4c's cut clarity, carat, color. , facts about spinel. physical properties of spinel, chemical properties of spinel.

1. RED SPINEL

2. Spinel is most often cut in
cushion and oval shapes;
when properly
proportioned it has
excellent brilliance.
The finest red Spinel is
pure red to slightly
purplish red hues of
medium to medium-dark
tone.
Like Ruby, Spinel is found
in alluvial deposits; it
ranks 8 on the mohs scale
and has good toughness,
making it a durable gem
for jewelry.
Well-formed Spinel
crystals are in high
demand among mineral
collectors.
Spinel belongs to the
cubic crystal system and
its characteristic crystal
shape is an octahedron,
which looks like two back
to back pyramids.Like ruby, the color of red
Spinel is due to traces of
Chromium

3. HISTORY OF SPINEL

4. •Spinel is the name given to the red gemstones that have been associated
with rubies throughout their history.
•The origin of the name is believed to have come from the Latin word,
spina which means 'little thorn',
•The Badakhshan mines were of great importance, and one of the earliest
references to them occurs in the diary of Marco Polo (1254 - 1324 AD).
•In the past, there was no distinction between true Ruby and Ruby Spinel, as
they look very similar and are found together in the same localities.
•The famous Black Prince's Ruby that forms the centerpiece of the royal crown
of Great Britain was discovered to be a Spinel rather then a Ruby.

5. Facts
• NAT THWE
Spinel crystals are so perfect, in Burma they are said to
be nat thwe or “polished by the spirits.”
• BLACK PRINCE
The famous 14th century Black Prince’s Ruby in the
British Imperial Crown is actually a red Spinel.
• 1783
Mineralogist Jean Baptiste Louis Rome de Lisle
identifies Spinel as a different mineral than ruby.

6. • Composed of magnesium aluminates, and
colored by chromium and iron.
• It is quite hard (8 on the Mohs scale), and it
forms as cubic crystals like diamond.
• Occurs in octahedral crystals.
• Has a complete absence
of cleavage (unlike diamond).
• Spinel is singly refractive.

7. • Spinel forms as a contact metamorphic mineral in
limestone.
• It is discovered as rolled pebbles in sand and gravel
pits.
• Nowadays, spinel is mined primarily in Burma, Sri
Lanka, Tanzania and Tajikistan, often alongside
corundum (ruby and sapphire).
• Any spinel gem weighing over two carats is rare.
• One of the attractions of spinel is that it comes in a
wide range of gorgeous colors. For red spinel, the
finest colors tend to be similar to ruby, (i.e. a rich,
intense red similar to that of a red traffic signal).

8. Color
Comes in variety
of colors and the
most desired is
red color
Clarity
No inclusions
visible to naked
eye
Carat
Larger spinel
sizes rise
considerably in
per-carat price.
Cut
Spinel is cut in a
variety of shapes
and cutting
styles., ovals and
cushion shapes
are very popular.