| General Information |
|---|
| Chemical Formula | Michael O’Donoghue, Gems, Sixth Edition (2006) More from other references |
|---|
| Physical Properties of Ludlamite |
|---|
| Mohs Hardness | 3 to 4Ulrich Henn and Claudio C. Milisenda, Gemmological Tables (2004) More from other references |
|---|
| Specific Gravity | 3.10Ulrich Henn and Claudio C. Milisenda, Gemmological Tables (2004) More from other references |
|---|
| Cleavage Quality | PerfectUlrich Henn and Claudio C. Milisenda, Gemmological Tables (2004) More from other references |
|---|
| Fracture | UnevenArthur Thomas, Gemstones (2009) |
|---|
| Optical Properties of Ludlamite |
|---|
| Refractive Index | 1.653 to 1.693Ulrich Henn and Claudio C. Milisenda, Gemmological Tables (2004) More from other references |
|---|
| Optical Character | Biaxial/+Ulrich Henn and Claudio C. Milisenda, Gemmological Tables (2004) More from other references |
|---|
| Birefringence | 0.040Ulrich Henn and Claudio C. Milisenda, Gemmological Tables (2004) More from other references |
|---|
| Pleochroism | NilArthur Thomas, Gemstones (2009) |
|---|
| Dispersion | Relatively weakArthur Thomas, Gemstones (2009) |
|---|
| Colour |
|---|
| Colour (General) | Apple- to bright-greenMichael O’Donoghue, Gems, Sixth Edition (2006) More from other references |
|---|
| Transparency | TransparentUlrich Henn and Claudio C. Milisenda, Gemmological Tables (2004) More from other references |
|---|
| Lustre | VitreousArthur Thomas, Gemstones (2009) |
|---|
| Crystallography of Ludlamite |
|---|
| Crystal System | MonoclinicUlrich Henn and Claudio C. Milisenda, Gemmological Tables (2004) More from other references |
|---|
| Habit | PrismaticMichael O’Donoghue, Gems, Sixth Edition (2006) More from other references |
|---|
| Geological Environment |
|---|
| Where found: | Occurs in granite pegmatites, resulting from the alteration of primary phosphatesMichael O’Donoghue, Gems, Sixth Edition (2006) |
|---|
| Further Information |
|---|
| Mineral information: | Ludlamite information at mindat.org |
|---|
| Significant Gem Localities |
|---|
| USA | |
- Blackbird Mining District
| Gems, Sixth Edition, Michael O’Donoghue, 2006, p. 425 |
|
|
