Administrative Assistant
Avamere Skilled Advisors, LLC
Administrative Assistant
marianaminerals· General
About this role
About Mariana Minerals
Mariana Minerals is a software-first, vertically integrated minerals company on a mission to supply the critical minerals powering modern energy, AI, and defense technologies. We’re reimagining the minerals supply chain by combining deep industry expertise with advanced software, automation, and data-driven decision-making.
The Role
We are seeking a highly organized and proactive Administrative Assistant to support day-to-day administrative operations at our Houston office. This role is ideal for someone early in their career who is detail-oriented, resourceful, and eager to grow within an operations or executive support function.
The Administrative Assistant will provide administrative support to the CFO, including calendar and travel coordination and expense management, while also supporting day-to-day office operations. The role will also serve as backup to the Executive Assistant as needed. This position requires strong communication skills, flexibility, sound judgment, and the ability to manage competing priorities in a fast-paced environment.
What You’ll Do
Administrative & Calendar Support
Assist with scheduling meetings, managing calendars, and coordinating internal and external appointments
Help prepare meeting materials, agendas, and notes as needed
Support coordination of cross-functional meetings and company events
Travel & Logistics
Book and manage domestic and international travel (flights, hotels, ground transportation)
Handle last-minute travel changes and troubleshoot logistical issues
Expense & Reporting Support
Prepare and submit expense reports in a timely and accurate manner
Reconcile receipts and assist with tracking budgets or spending reports
On-Site & Office Support
Provide in-office support as needed
Coordinate office supplies, deliveries, and facilities-related requests
Assist with visitor management and on-site meeting logistics
Support internal events and team off-sites
Executive Assistant Backup
Serve as backup to the Executive Assistant during absences
Provide overflow support during high-volume periods
Assist with special projects and ad hoc requests
Desired Qualifications
1–3+ years of administrative or office support experience preferred
Strong organizational skills and attention to detail
Excellent written and verbal communication skills
Proficiency in Microsoft Office
Experience with expense management and calendar systems preferred
Ability to handle confidential information with discretion
Strong time management and prioritization skills
Problem-solving mindset
Professional and service-oriented approach
Adaptability in a fast-paced environment
Team player with a positive attitude
Our culture is built on four principles:
Everyone Gets Home Safe. We never put speed or cost ahead of people.
Extreme Ownership. We take full responsibility for outcomes, relentlessly driving toward solutions.
Engineer Out Requirements, then Automate. We simplify, optimize, and then automate for scale.
Share Your Legos. We collaborate openly, share knowledge, and empower each other to build bigger, better solutions.
Join us as we build the future of responsible mineral sourcing and supply!
Frequently Asked Questions
Is the salary disclosed for the Administrative Assistant position at marianaminerals?
The salary for this Administrative Assistant role at marianaminerals is not publicly listed. Click "Apply Now" to learn more about the compensation package on their official careers page.
Where is the Administrative Assistant position at marianaminerals located?
This Administrative Assistant role at marianaminerals is based in Houston, TX. The position is listed as on-site or hybrid. Check the full job description or apply directly to confirm the work arrangement.
Is the Administrative Assistant role at marianaminerals full-time or part-time?
This is listed as a FullTime position. It is posted as a Administrative Assistant role in the General department at marianaminerals.
Which team or department does the Administrative Assistant at marianaminerals belong to?
This Administrative Assistant position is part of the General department at marianaminerals. See the full job description for more information about the team structure and responsibilities.
How do I apply for the Administrative Assistant position at marianaminerals?
Click the "Apply Now" button on this page. You will be redirected to marianaminerals's official application portal hosted on ashby where you can submit your application directly.
When was the Administrative Assistant job at marianaminerals posted?
This Administrative Assistant position at marianaminerals was posted on Aug 26, 2026. Apply as soon as possible — early applications are often reviewed first.
Administrative Assistant
marianaminerals
You'll be redirected to marianaminerals's official application page on Ashby ATS.