Check the listing for details. Native Silver Copper Halfbreed Specimen Michigan 10.45 gm 26 mm. Listed at 85.00 USD. Native Silver Copper Halfbreed Mineral Specimen Michigan 10.45 gm 26 x 21 mm DescriptionBeautiful specimen of native silver on native copper formation with copper ore matrix. The colors are very beautiful with the silver and oxidized copper in contrast with the areas of matrix ore. Native copper has been mined for centuries and now is all but depleted, though it is still found in limited quantities in once-active mining regions. Native silver is even more rare. These finds are now valuable as mineralogical specimens and ornamental pieces. From Keweenaw County, Upper Peninsula, Michigan, USA. Physical Characteristics:Silver Color is silver white. Luster is metallic.Transparency is opaque.Crystal System is isometric; 4/m bar 3 2/mCrystal Habits include massive and disseminated grains. "Jack Frost" type crystal growth produces beautiful intricate structures.Cleavage is absent.Fracture is jagged.Streak is silver white.Hardness is 2.5-3.Specific Gravity is variable according to purity 10-12 (well above average even for metallic minerals) CopperColor is copper colored with natural patinaLuster is metallic.Transparency is opaque.Crystal System is isometric; 4/m bar 3 2/mCrystal Habit is arborescent or branching form.Cleavage is absent.Fracture is jagged.Streak is reddish copper color.Hardness is 2.5-3Specific Gravity is 8.9+ (above average for metallic)Dimensions: 26mm x 21mm A specimen like this is rarely found. Gold Jewelers Gift Box included This will be shipped First Class Mail for fast safe arrival to you.FREE SHIPPING and INSURANCE! Thank you.