Hackmanite: ハックマン石 Na4Al3Si3O12Cl
Etymology: from the finnsih geologist’s name Victor Hackman.
A light, relatively hard yet fragile mineral, sodalite is named after its sodium content. In mineralogy it may be classed as a feldspathoid
Originally described from Tawa valley, Kola Peninsula, Murmanskaja Oblast’, Northern Region, Russia.
In the dark this gem becomes almost white. It turns viloet - purple under light.
Hambergite: Be2BO3(OH)
Etymology: dedicated to the Swedish mineralogist Axel Hamberg.
Hardness: 7.5
Crystal system: orthorhombic.
Haüy:
Abbot René Just Haüy was born on February 28, 1743 in Saint-Just-en-Chaussée, France, in the department of Oise and died on June 3, 1822 in Paris. He was the founder of modern mineralogy (and the brother of Valentin who dedicated his life to helping the blind). Holding a chair at the Faculty of Art at the Sorbonne, he taught mineralogy at the National Museum of Natural History from 1802 through 1822.
Haüy proved that the form of crystals came from a small number of what he called "Integrant molecules" and which was later named crystalline systems.
Hauyne: (Na,Ca)8-4(SO4)2-1
Etymology: gem dedicated to Abbot René Just Haüy, famous French mineralogist and crystallogist. (1743-1822).
Discovered in 1807 by Brunn-Neegard in Italy (Monte Somma, Mt Vesuvius.) The only cuttable gem crystals come from Effel in Germany. They range from turquoise blue to an intense sea blue.
Hauyne is part of the composition of lapis lazuli.
_ Refractive index: 1.49/1.50.
Hardness: 5.5/6.
Crystal system: cubic._ See Gallery
Heliodore: ヘリオドール Al2Be3(Si6O18).
Etymology: from the Greek « Helios » = sun.
The yellow variety of beryl.
Refractive index: 1.57/1.59.
Hardness: 7.5
Crystal system: hexagonal.
See Gallery
Herderite: CaBe(PO4)F 
Etymology: gem dedicated to the Baron Siegmund A.W. VON HERDER, Officer of the Mines of Freiberg (1776-1838 ) in Germany. Discovered in 1828 at Ehrenfriedersdorf, Saxe, Allemagne.
Hardness: 5/5.5
Crystal system: monoclinic.
See Gallery
Hematite:
Etymology: from Latin "Haematites" = blowd, regarding its red color when it is in powder.
Auhtor Pline in 77
See galerie
Hemimorphite: 
Etymology: from the Greek "hemi" = half and "morphos" = shape. Discovered in 1853 by Kenngott.
Refractive index: 1.61-1.63.
Hardness: 6.5
Crystal system: orthorhombic.
See Gallery
Heze: 
_ Meteorite named after the Chinese location where it was found.
See Gallery
Hibonite : (Ca,Ce)(Al,Ti,Mg)12O19 
Ethymologie : This rather rare
mineral was named after Paul Hibon, the French prospector
who discovered it.
This mineral was known since 1955 in Madagascar as opaque blacks crystals or grains. Hibonite occurs also in meteorites.
two transparent orangy brown crystals
weighing 0.23 and 0.71 g g (7.02 x 7.32 x 5.44mm) were submitted to the AIGS Gemological Laboratory in Bangkok for
identification. The crystals were said to originate from Burma.
The 0.23g crystal was faceted (0.39ct) and the 0.71g was kept like this.
These 2 crystals are the only 2 Hibonite known in gem quality.
Gemfrance.com is the owner of the 0.71g crystal.
This new gem have been analysed and the results have been published in Gems and Gemology: Thomas Hainschwang, Franck Notari, Laurent Massi, Thomas Armbruster, Benjamin Rondeau, Emmanuel Fritsch, et Mariko Nagashima - GEMS & GEMOLOGY, Vol. 46, No. 2, pp. 135-138. © 2010 Gemological Institute of America .
Proprieties:
Hexagonal - Uniaxial negative - IR : 1.79 - 1.81 - Mohs hardness : 7.5-8 - SG : 3.84 -No fluorescence.
You can obtain the full article in PDF by folowing this link ->
Hiddenite: LiAlSi2 O6. 
Etymology: the name of this gem comes from W. E. Hidden who discovered it in 1879, in North Caroline (USA).
The green variety of Spodumene.
Refractive index: 1.66
Hardness: 6.5
Crystal system: monoclinic.
See Gallery
Hollandite: Ba (Mn+4,Mn+2)8 O16
Etymology: mineral discovered by Fermor in 1906. The name is dedicated T.H. HOLLAND, directer of the Geological Service of India.
Location of origin: KAJLIDONGRI, THE STATE OF JHABUA (India).
Hollandite belongs to the Cryptomelane group.
See Gallery Quartz with Hollandite.
